Answer:
[tex]y=3e^{-4t}[/tex]
Step-by-step explanation:
[tex]y''+5y'+4y=0[/tex]
Applying the Laplace transform:
[tex]\mathcal{L}[y'']+5\mathcal{L}[y']+4\mathcal{L}[y']=0[/tex]
With the formulas:
[tex]\mathcal{L}[y'']=s^2\mathcal{L}[y]-y(0)s-y'(0)[/tex]
[tex]\mathcal{L}[y']=s\mathcal{L}[y]-y(0)[/tex]
[tex]\mathcal{L}[x]=L[/tex]
[tex]s^2L-3s+5sL-3+4L=0[/tex]
Solving for [tex]L[/tex]
[tex]L(s^2+5s+4)=3s+3[/tex]
[tex]L=\frac{3s+3}{s^2+5s+4}[/tex]
[tex]L=\frac{3(s+1)}{(s+1)(s+4)}[/tex]
[tex]L=\frac3{s+4}[/tex]
Apply the inverse Laplace transform with this formula:
[tex]\mathcal{L}^{-1}[\frac1{s-a}]=e^{at}[/tex]
[tex]y=3\mathcal{L}^{-1}[\frac1{s+4}]=3e^{-4t}[/tex]
A medical researcher wishes to estimate what proportion of babies born at a particular hospital are born by Caesarean section. In a random sample of 49 births at the hospital, 32% were Caesarean sections. Find the 95% confidence interval for the population proportion
Answer: (0.1828,0.4572)
Step-by-step explanation:
Given : A medical researcher wishes to estimate what proportion of babies born at a particular hospital are born by Caesarean section.
Sample size : n= 49
Proportion of babies were Caesarean sections : [tex]\hat{p}=0.32[/tex]
Significance level : [tex]\alpha =1-0.95=0.05[/tex]
Standard error : [tex]S.E.=\sqrt{\dfrac{\hat{p}(1-\hat{p})}{n}}[/tex]
[tex]=\sqrt{\dfrac{0.32\times0.68}{49}}=0.06663945022\approx0.07[/tex]
Margin of error : [tex]E=z_{\alpha/2}\times S.E.[/tex]
[tex]=z_{0.025}\times0.07=1.96\times0.07=0.1372[/tex]
The confidence interval for the population proportion is given by :-
[tex]\hat{p}\pm E[/tex]
[tex]=0.32\pm0.1372=(0.1828,0.4572)[/tex]
The question pertains to calculating the 95% confidence interval for the proportion of babies born by Caesarean section at a specific hospital, given a sample size of 49 births and a sample proportion of 32%. The answer shows how to use the confidence interval formula for a proportion (p ± Z * √((p*(1-p))/n)) and provides a calculation.
Explanation:The subject of this question involves using statistics to calculate a confidence interval for a population proportion. In this context, the population proportion is the proportion of babies born by Caesarean section at a particular hospital.
We are provided with a random sample of 49 births, and within this sample, 32% were Caesarean sections. To answer this question about confidence intervals, we need to use a formula for the confidence interval of a proportion. The formula is p ± Z * √((p*(1-p))/n), where p is the proportion in the sample (0.32 in this case), Z is the Z-score from the Z-table associated with the desired confidence level (Z=1.96 for 95% confidence), and n is the number of observations (49).
Plugging the values in the formula, we get 0.32 ± 1.96 * √((0.32*(1-0.32))/49). When you calculate that, you will get a 95% confidence interval for the population proportion of Caesarean sections at this hospital.
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For what values of a and b is the line 4x + y = b tangent to the parabola y = ax2 when x = 4?
The values of 'a' and 'b' for which the line 4x + y = b is tangent to the parabola[tex]y = ax^2[/tex] at x = 4 are a = -1/2 and b = 8.
To find the values of a and b for which the line 4x + y = b is tangent to the parabola [tex]y = ax^2[/tex] when x = 4, we need to ensure that the line and the parabola have the same slope at the point of tangency.
Convert the equation to the slope-intercept form (y = mx + c), where m is the slope and c is the y-intercept.
4x + y = b
y = -4x + b
The slope (m) of the line is -4.
Now find the slope of the parabola y = ax^2 when x = 4:
To do this, find the derivative of the parabola with respect to x and then evaluate it at x = 4.
[tex]y = ax^2[/tex]
dy/dx = 2ax (derivative of ax^2 with respect to x)
Now, evaluate the derivative at x = 4:
dy/dx = 2a(4)
= 8a
The slope (m) of the parabola [tex]y = ax^2[/tex] when x = 4 is 8a.
Equate the slopes of the line and the parabola at x = 4:
We want the slopes of both the line and the parabola to be equal at x = 4:
-4 = 8a
Now, solve for 'a':
a = -4/8
a = -1/2
To find the value of 'b' by substituting 'a' and the given point (x = 4, [tex]y = ax^2[/tex]) into the equation of the line:
y = -4x + b
y = -4(4) + b
y = -16 + b
Now, set [tex]ax^2 = -16 + b[/tex], and substitute the value of 'a' we found earlier:
[tex]\frac{-1}{2}(4)^2 = -16 + b[/tex]
[tex]\frac{-1}{2}(16) = -16 + b[/tex]
[tex]-8 = -16 + b[/tex]
[tex]b=8[/tex]
Hence, the values of 'a' and 'b' for which the line 4x + y = b is tangent to the parabola[tex]y = ax^2[/tex] at x = 4 are a = -1/2 and b = 8.
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Final answer:
The values of a and b are calculated to be 1/2 and 24, respectively, by solving simultaneous equations based on these conditions.
Explanation:
The question asks for the values of a and b where the line 4x + y = b is tangent to the parabola y = ax2 at x = 4.
To find these values, we need to satisfy two conditions: the line and the parabola must intersect at x = 4, and their slopes at this point must be equal, as this characterizes tangency.
First, solve the equation of the parabola for x = 4: y = a(4)2 = 16a.
Substituting x = 4 into the equation of the line gives 4(4) + y = b, or 16 + y = b.
Since the line and the parabola intersect at this point, their y-values must be equal, hence 16 + 16a = b.
To find the values of a, we must equate the slopes of the tangent line and the parabola at x = 4.
The slope of the line is the coefficient of x, which is 4. The slope of the parabola at any point x is derived by differentiating y = ax2, giving dy/dx = 2ax.
At x = 4, the slope is 2a(4) = 8a, which must equal the slope of the line, 4. Therefore, 8a = 4, and a = 1/2.
Substituting a = 1/2 into 16 + 16a = b gives b = 16 + 8 = 24.
Therefore, the values of a and b for which the line is tangent to the parabola at x = 4 are a = 1/2 and b = 24.
CAN ANYONE AT LEAST HELP ME AND DIRECT ME IN THE RIGHT DIRECTION ON HOW TO DO THESE? PLEASE IT IS DUE TOMORROW
Use a table of values to graph the functions given on the same grid
p(x) = x^2, q(x) = x^2-4, r(x) = x^2 + 1
Answer:
Step-by-step explanation:
We need to graph the functions
p(x) = x^2
q(x) = x^2 - 4
r(x) = x^2 +1
the table used to draw the graph is:
x p(x) q(x) r(x)
-2 4 0 5
-1 1 -3 2
0 0 -4 1
1 1 -3 2
2 4 0 5
The graph is attached below.
In terms of explaining the probability of assignment to trial arms in consent forms, ICH notes that is should be included...True or False
Answer: True, hope this helps! :)
In a survey of adults who follow more than one sport, 30% listed football as their favorite sport. You survey 15 adults who follow more than one sport. What is the probability rounded to the nearest tenth that fewer than 4 of them will say that football is their favorite sport?
Answer: 0.5
Step-by-step explanation:
Binomial probability formula :-
[tex]P(x)=^nC_x\ p^x(q)^{n-x}[/tex], where P(x) is the probability of getting success in x trials , n is the total trials and p is the probability of getting success in each trial.
Given : The probability that the adults follow more than one game = 0.30
Then , q= 1-p = 1-0.30=0.70
The number of adults surveyed : n= 15
Let X be represents the adults who follow more than one sport.
Then , the probability that fewer than 4 of them will say that football is their favorite sport,
[tex]P(X\leq4)=P(x=0)+P(x=1)+P(x=2)+P(x=3)+P(x=4)\\\\=^{15}C_{0}\ (0.30)^0(0.70)^{15}+^{15}C_{1}\ (0.30)^1(0.70)^{14}+^{15}C_{2}\ (0.30)^2(0.70)^{13}+^{15}C_{3}\ (0.30)^3(0.70)^{12}+^{15}C_{4}\ (0.30)^4(0.70)^{11}\\\\=(0.30)^0(0.70)^{15}+15(0.30)^1(0.70)^{14}+105(0.30)^2(0.70)^{13}+455(0.30)^3(0.70)^{12}+1365(0.30)^4(0.70)^{11}\\\\=0.515491059227\approx0.5[/tex]
Hence, the probability rounded to the nearest tenth that fewer than 4 of them will say that football is their favorite sport =0.5
Certain functions obey the property f(m + n)=f(m)f(n) for all positive numbers and n.Can you think of a function that obeys this property? Hint: Functions that obey this property ill be familiar from ordinary pre-calculus algebra courses. Same question, but this time, the property is f(mn) f(m) +f(n) . (Note, don't expect f to be integer-valued. The hint from the first part applies here too.) m
Answer:
Given
[tex]f(m+n)=f(m)f(n)[/tex]
If we assume
[tex]f(x)=ae^{x}\\\\f(m+n)=ae^{m+n}\\\\\therefore f(m+n)=ae^{m}\times ae^{n}(\because x^{a+b}=x^{a}\times x^{b})\\\\\Rightarrow f(m+n)=f(m)\times f(n)[/tex]
Similarly
We can generalise the result for
[tex]f(x)=am^{x }[/tex] where a,m are real numbers
2)
[tex]f(m\cdot n)=f(m)+f(n)\\\\let\\f(x)=log(x)\\\therefore f(mn)=log(mn)=log(m)+log(n)\\\\\therefore f(mn)=f(m)+f(n)[/tex]
List all the bijections from A into B.
a) A={q,r,s} and B={2,3,4}
b) A={1,2,3,4} and B={5,6,7,8}
Answer:
The list of bijections from A into B are shown below.
Step-by-step explanation:
A function f is called one-to-one or injective, if and only if
[tex]f(x)=f(y)\Rightarrow x = y[/tex]
for all x and y in the domain of f.
A function f from X to Y is called onto or surjective, if and only if
for every element y∈Y there is an element x∈X with f(x)=y.
If a function is one-one and onto, then it is called bijective.
Part (a):
A={q,r,s} and B={2,3,4}
We need to find all the bijections from A into B.
(1) [tex]A\rightarrow B=\{(q,2),(r,3),(s,4)\}[/tex]
(2) [tex]A\rightarrow B=\{(q,2),(r,4),(s,3)\}[/tex]
(3) [tex]A\rightarrow B=\{(q,3),(r,2),(s,4)\}[/tex]
(4) [tex]A\rightarrow B=\{(q,3),(r,4),(s,2)\}[/tex]
(5) [tex]A\rightarrow B=\{(q,4),(r,2),(s,3)\}[/tex]
(6) [tex]A\rightarrow B=\{(q,4),(r,3),(s,2)\}[/tex]
Part (b):
A={1,2,3,4} and B={5,6,7,8}
We need to find all the bijections from A into B.
(1) [tex]A\rightarrow B=\{(1,5),(2,6),(3,7),(4,8)\}[/tex]
(2) [tex]A\rightarrow B=\{(1,5),(2,6),(3,8),(4,7)\}[/tex]
(3) [tex]A\rightarrow B=\{(1,5),(2,7),(3,6),(4,8)\}[/tex]
(4) [tex]A\rightarrow B=\{(1,5),(2,7),(3,8),(4,6)\}[/tex]
(5) [tex]A\rightarrow B=\{(1,5),(2,8),(3,6),(4,7)\}[/tex]
(6) [tex]A\rightarrow B=\{(1,5),(2,8),(3,7),(4,6)\}[/tex]
(7) [tex]A\rightarrow B=\{(1,6),(2,5),(3,7),(4,8)\}[/tex]
(8) [tex]A\rightarrow B=\{(1,6),(2,5),(3,8),(4,7)\}[/tex]
(9) [tex]A\rightarrow B=\{(1,6),(2,7),(3,5),(4,8)\}[/tex]
(10) [tex]A\rightarrow B=\{(1,6),(2,7),(3,8),(4,5)\}[/tex]
(11) [tex]A\rightarrow B=\{(1,6),(2,8),(3,5),(4,7)\}[/tex]
(12) [tex]A\rightarrow B=\{(1,6),(2,8),(3,7),(4,5)\}[/tex]
(13) [tex]A\rightarrow B=\{(1,7),(2,6),(3,5),(4,8)\}[/tex]
(14) [tex]A\rightarrow B=\{(1,7),(2,6),(3,8),(4,5)\}[/tex]
(15) [tex]A\rightarrow B=\{(1,7),(2,5),(3,6),(4,8)\}[/tex]
(16) [tex]A\rightarrow B=\{(1,7),(2,5),(3,8),(4,6)\}[/tex]
(17) [tex]A\rightarrow B=\{(1,7),(2,8),(3,6),(4,5)\}[/tex]
(18) [tex]A\rightarrow B=\{(1,7),(2,8),(3,5),(4,6)\}[/tex]
(19) [tex]A\rightarrow B=\{(1,8),(2,6),(3,7),(4,5)\}[/tex]
(20) [tex]A\rightarrow B=\{(1,8),(2,6),(3,5),(4,7)\}[/tex]
(21) [tex]A\rightarrow B=\{(1,8),(2,7),(3,6),(4,5)\}[/tex]
(22) [tex]A\rightarrow B=\{(1,8),(2,7),(3,5),(4,6)\}[/tex]
(23) [tex]A\rightarrow B=\{(1,8),(2,5),(3,6),(4,7)\}[/tex]
(24) [tex]A\rightarrow B=\{(1,8),(2,5),(3,7),(4,6)\}[/tex]
Call a household prosperous if its income exceeds $100,000. Call the household educated if the householder completed college. Select an American household at random, and let A be the event that the selected household is prosperous and B the event that it is educated. According to the Current Population Survey, P(A)=0.138, P(B)=0.261, and the probability that a household is both prosperous and educated is P(A and B)=0.082. What is the probability P(A or B) that the household selected is either prosperous or educated?
Answer: 0.317
Step-by-step explanation:
Let A be the event that the selected household is prosperous and B the event that it is educated.
Given : P(A)=0.138, P(B)=0.261
P(A and B)=0.082
We know that for any events M and N ,
[tex]\text{P(M or N)=P(M)+P(N)-P(M or N)}[/tex]
Thus , [tex]\text{P(A or B)=P(A)+P(B)-P(A or B)}[/tex]
[tex]\text{P(A or B)}=0.138+0.261-0.082\\\\\Rightarrow\text{ P(A or B)}=0.317[/tex]
Hence, the probability P(A or B) that the household selected is either prosperous or educated = 0.317
Final answer:
The probability that a randomly selected American household is either prosperous or educated is 0.317.
Explanation:
We are asked to find the probability P(A or B) that a randomly selected American household is either prosperous (income over $100,000) or educated (householder completed college). To calculate the probability of the union of two events A and B, we use the formula:
P(A or B) = P(A) + P(B) - P(A and B).
According to the given data:
P(A) is the probability that a household is prosperous, which is 0.138.
P(B) is the probability that a household is educated, which is 0.261.
P(A and B) is the probability that a household is both prosperous and educated, which is 0.082.
Now we apply the given probabilities to the formula:
P(A or B) = 0.138 + 0.261 - 0.082 = 0.317.
Therefore, the probability that a selected household is either prosperous or educated is 0.317.
Question 3: What is the x-intercept of the line 3x+4y=12?
Question 3 options:
(4, 0)
(3, 0)
(0, 4)
(0, 3)
Answer: First option.
Step-by-step explanation:
It is important to remember that the line intersects the x-axis when [tex]y=0[/tex].
So, given the line [tex]3x+4y=12[/tex], you need to substitute [tex]y=0[/tex] into the equation and solve for "x", in order to find the x-intercept of this line.
Therefore, this is:
[tex]3x+4y=12\\\\3x+4(0)=12\\\\3x+0=12\\\\3x=12\\\\x=\frac{12}{3}\\\\x=4[/tex]
Therefore, this line intersects the x-axis at this point:
[tex](4,0)[/tex]
Suppose babies born in a large hospital have a mean weight of 3242 grams, and a standard deviation of 446 grams. If 107 babies are sampled at random from the hospital, what is the probability that the mean weight of the sample babies would differ from the population mean by less than 40 grams? Round your answer to four decimal places.
Final answer:
To find the probability that the mean weight of a sample of 107 babies differs from the population mean by less than 40 grams, we can use the Central Limit Theorem. The probability is approximately 0.0441.
Explanation:
To find the probability that the mean weight of a sample of 107 babies differs from the population mean by less than 40 grams, we can use the Central Limit Theorem. According to the Central Limit Theorem, the distribution of sample means will be approximately normal as long as the sample size is large enough. In this case, our sample size is 107, which is considered large enough.
The formula to calculate the standard deviation of the sampling distribution of the sample mean is sigma/sqrt(n), where sigma is the population standard deviation and n is the sample size. Plugging in the values, we have 446/sqrt(107) = 42.96 grams.
To find the probability, we need to calculate the z-score for a difference of 40 grams from the population mean. The z-score formula is (x - mu) / (sigma / sqrt(n)), where x is the desired difference, mu is the population mean, sigma is the population standard deviation, and n is the sample size.
Plugging in the values, we have (40 - 3242) / (446/sqrt(107)) = -1.7. We want to find the probability that the z-score is less than -1.7. Using a standard normal distribution table or calculator, we find that the probability is approximately 0.0441.
To solve this question, we can use the Central Limit Theorem (CLT), which implies that the sampling distribution of the sample means will be normally distributed if the sample size is large enough (usually n > 30 is considered sufficient). Since we are dealing with a sample of 107 babies, which is quite large, we can safely use the CLT.
According to the CLT, the mean of the sample means will be equal to the population mean (μ), and the standard deviation of the sample means (often called the standard error, SE) will be equal to the population standard deviation (σ) divided by the square root of the sample size (n).
Given:
- The population mean (μ) = 3242 grams
- The population standard deviation (σ) = 446 grams
- The sample size (n) = 107 babies
First, we must calculate the standard error (SE):
SE = σ / √n
SE = 446 grams / √107
SE ≈ 446 grams / 10.344
SE ≈ 43.13 grams
Now, we want to find the probability that the mean weight of the sample babies would differ from the population mean by less than 40 grams. This means we are looking at weights from (μ - 40) grams to (μ + 40) grams.
So we will find the z-scores corresponding to (μ - 40) grams and (μ + 40) grams:
Z = (X - μ) / SE
For the lower limit (μ - 40 grams = 3202 grams):
Z Lower = (3202 - 3242) / 43.13
Z Lower ≈ -40 / 43.13
Z Lower ≈ -0.927
For the upper limit (μ + 40 grams = 3282 grams):
Z Upper = (3282 - 3242) / 43.13
Z Upper ≈ 40 / 43.13
Z Upper ≈ 0.927
Using the standard normal distribution (Z-distribution), we can find the probability that a Z-score falls between -0.927 and 0.927. These values correspond to the area under the standard normal curve between these two Z-scores.
If we look these values up in a Z-table, or use a calculator:
- The probability of Z being less than 0.927 is approximately 0.8238.
- The probability of Z being less than -0.927 is approximately 0.1762.
So, the probability of the mean weight being between μ - 40 grams and μ + 40 grams is the area between these two Z-scores, which can be found by subtracting the lower probability from the upper probability:
P(-0.927 < Z < 0.927) = P(Z < 0.927) - P(Z < -0.927)
P(-0.927 < Z < 0.927) = 0.8238 - 0.1762
P(-0.927 < Z < 0.927) = 0.6476
Rounding to four decimal places:
P(-0.927 < Z < 0.927) ≈ 0.6476
Therefore, the probability that the mean weight of the sample babies would differ from the population mean by less than 40 grams is approximately 0.6476, or 64.76%.
A bag contains three types of coins i.e. one rupee coins, 50 paisa coins and 25 paisa coins totalling 175 coins. If the total value of the coins of each kind be the same, the total amount in the bag is
a) Rs 300 b) Rs 175 c) Rs 126 d) Rs 75
one rupee coin be z
50 paisa coins=2z
25 paisa coins=4z
50/25=2 2z*2=4z
z+2x+4x=175
7z=175
7z/7=175/7
z=25
one rupee coin=25 value
50 paisa rupee coins=50 value
25 rupee coin=100 value
50/25=2 50*2=100
25+50+100=175
Answer is b) Rs 175. I think this is the answer.
120 hardness measurements are made on a large slab of steel with an average of Rockwell C value of 39 and a standard deviation of 4.0. What percent of measurements should fall between 35 and 45?
Answer: 77.45 %
Step-by-step explanation:
We assume that the measurements are normally distributed.
Given : Mean : [tex]\mu=39[/tex]
Standard deviation : [tex]\sigma=4.0[/tex]
Let x be the randomly selected measurement.
Now we calculate z score for the normal distribution as :-
[tex]z=\dfrac{x-\mu}{\sigma}[/tex]
For x = 35, we have
[tex]z=\dfrac{35-39}{4}=-1[/tex]
For x = 45, we have
[tex]z=\dfrac{45-39}{4}=1.5[/tex]
Now, the p-value = [tex]P(35<x<45)=P(-1<z<1.5)[/tex]
[tex]=P(z<1.5)-P(z<-1)\\\\=0.9331927-0.1586553=0.7745374\approx0.7745[/tex]
In percent , [tex]0.7745\times100=77.45\%[/tex]
Hence, the percent of measurements should fall between 35 and 45 = 77.45 %
Final answer:
Approximately 68% of the hardness measurements on the Rockwell C scale should fall between 35 and 45, according to the empirical rule and the provided mean and standard deviation.
Explanation:
To determine the percentage of hardness measurements that fall between 35 and 45 on the Rockwell C scale, we utilize the concept of standard deviation and the empirical rule.
Given the average (or mean) Rockwell C value is 39 and the standard deviation is 4.0, the range from 35 to 45 encompasses from one standard deviation below to one standard deviation above the mean.
According to the empirical (68-95-99.7) rule, about 68% of data within a normal distribution falls within one standard deviation of the mean.
Since the range from 35 to 45 represents this bracket around the mean, we can conclude that approximately 68% of the hardness measurements should fall within this range, assuming a normal distribution of the measurements.
The displacement (in centimeters) of a particle moving back and forth along a straight line is given by the equation of motion
s = 4 sin(πt) + 3 cos(πt),
where t is measured in seconds. (Round your answers to two decimal places.)
A. Find the average velocity during each time period.
(i) [1, 2]
(ii) [1, 1.1]
(iii) [1, 1.01]
(iv) [1, 1.001]
B. Estimate the instantaneous velocity of the particle when t = 1.
Answer:
Find the slope of the line that passes through the points shown in the table.
The slope of the line that passes through the points in the table is
.
Step-by-step explanation:
Use Lagrange multipliers to find the maximum and minimum values of (i) f(x,y)-81x^2+y^2 subject to the constraint 4x^2+y^2=9. (ii) f(x,y,z)=y^2-10z subject to the constraint x^2+y^2+z^2=36
To find maximum and minimum values using Lagrange multipliers, set up a Lagrangian function, apply the technique of setting partial derivatives to zero, and solve the resulting system of equations. This technique is applied to both given functions to solve for the variables and the multiplier.
Explanation:The subject of this question relates to the application of Lagrange multipliers in mathematics, specifically to find the maximum and minimum values of functions with constraints.
Starting with the first function, we set up the Lagrangian function L = f(x, y) - λ(g(x, y) - c) where λ is the Lagrange multiplier, and g(x, y) is the constraint. So, we get L = 81x^2 + y^2 - λ(4x^2 + y^2 -9). By setting the partial derivatives of L to zero and solving that system of equations, we can find x, y and λ.
For the second function, we apply the same process, the Lagrangian function will be L = y^2 - 10z - λ(x^2 + y^2 + z^2 - 36). Setting partial derivatives equal to zero and solving the resulting system will provide x, y, z, and λ.
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The maximum for the first problem is 182.25 and the minimum is 9, while the maximum for the second problem is 61.
To solve these problems using Lagrange multipliers, we need to find the maximum and minimum values of the given functions subject to the provided constraints.
(i) Function f(x,y) = 81x^2 + y² with Constraint 4x² + y² = 9
→ Define the Lagrangian function: L(x, y, λ) = 81x² + y² + λ(9 - 4x² - y²).
Compute the partial derivatives and set them to zero:
→ [tex]L_x = 162x - 8x\lambda = 0[/tex]
→ [tex]L_y = 2y - 2y\lambda = 0[/tex]
→ [tex]L\lambda = 9 - 4x^2 - y^2 = 0[/tex]
Solve the system of equations:
→ 162x = 8xλ
⇒ λ = 20.25
→ 2y = 2yλ
⇒ λ = 1 (y ≠ 0)
But we need a consistent value of λ; thus, solve considering different cases (y = 0):
→ If y = 0, constraint becomes 4x² = 9
⇒ x = ±√(9/4)
= ±3/2
→ If x = 0, constraint becomes y² = 9
⇒ y = ±3
Evaluate f(x, y) at these points:
→ f(3/2, 0) = 81 (3/2)²
= 81 * 2.25
= 182.25 (Maximum)
→ f(0, 3) = 3²
= 9
(ii) Function f(x, y, z) = y² - 10z with Constraint x² + y² + z² = 36
Define the Lagrangian function: L(x, y, z, λ) = y² - 10z + λ(36 - x² - y² - z²).
Compute the partial derivatives and set them to zero:
→ [tex]L_x = -2x\lambda = 0[/tex]
⇒ x = 0
→ [tex]L_y = 2y - 2y\lambda = 0[/tex]
⇒ y = 0 or λ = 1
→ [tex]L_z = -10 - 2z\lambda = 0[/tex]
⇒ λ = -5/z
→ [tex]L\lambda = 36 - x^2 - y^2 - z^2 = 0[/tex]
Solve the system of equations considering constraints:
Substituting values, x = 0 and λ = 1, we need to solve for y and z:
→ 36 = y² + z²
→ λ = -5/z;
Thus z = -5
Solving y² + 25 = 36, y² = 11
⇒ y = ±√11
Evaluate f(x, y, z) at these points:
→ f(0, √11, -5) = (√11)² - 10(-5)
= 11 + 50
= 61 (Maximum)
→ f(0, -√11, -5) = 61
The scores for today’s math quiz are 75, 95, 60, 75, 95, and 80. Explain the steps needed to create a histogram for the data.
Answer:
Sample Response: Determine what should go on each axis. Grades will go on the x-axis, and the number of students will be plotted on the y-axis. Find the number of different scores and range. Choose an interval – say, 10 percent. Find the frequency within each interval. Choose a scale – say, 0–3. Draw bars the height of the frequency for each interval.
Step-by-step explanation:
(Sample Response)
Creating a histogram is a way to visually represent the distribution of a dataset. Here's how you can create a histogram for today’s math quiz scores step by step:
### Step 1: Collect the Data
First, gather all the scores you want to include in the histogram. In this case, the scores are 75, 95, 60, 75, 95, and 80.
### Step 2: Determine the Number of Bins
Choose an appropriate number of bins (groups or class intervals) for your histogram. The number of bins can significantly affect the appearance of the histogram. There are different rules of thumb for this, such as using the square root of the number of data points. However, you often have to decide based on the range of your data and the level of granularity you want.
### Step 3: Determine the Bin Intervals
The bins are ranges of scores that your data will be split into. You need to ensure the bins collectively cover the entire range of your data. To do this, find the minimum and maximum scores. Then, decide how wide each bin should be. This can be done either by dividing the entire range by the number of bins or by choosing a bin width that makes sense practically.
### Step 4: Tally Scores in Each Bin
Go through your data and count how many scores fall into each bin range. For instance, if your first bin includes scores from 60 to 70, count all the scores that are within this range.
### Step 5: Draw the Histogram
On graph paper or using graphing software:
- Draw a horizontal axis (the x-axis) and a vertical axis (the y-axis).
- Label the horizontal axis with the score ranges for each bin.
- Label the vertical axis with the frequency (the number of scores in each bin).
- For each bin, draw a bar that reaches up to the frequency of scores in that bin. The width of each bar should correspond to the bin width, and there should be no space between bars if the data is continuous.
### Step 6: Label Your Histogram
Finally, provide a title for your histogram and label the axes to make it clear what is being represented.
Keep in mind that histograms should give a clear picture of how the data is distributed. If you have bins that are too large, you'll lose detail. If they're too small, the histogram may be too choppy to identify any trends. Adjust the number of bins and bin width accordingly if your first histogram doesn’t seem to represent your data clearly.
Two vectors A⃗ and B⃗ are at right angles to each other. The magnitude of A⃗ is 5.00. What should be the length of B⃗ so that the magnitude of their vector sum is 9.00?
Answer:
Length of B is 7.4833
Step-by-step explanation:
The vector sum of A and B vectors in 2D is
[tex]C=A+B=(a_1+b_1,a_2+b_2)[/tex]
And its magnitude is:
[tex]C=\sqrt{(a_1+b_1)^2+(a_2+b_2)^2} =9[/tex]
Where
[tex]a_1=Asinx[/tex]
[tex]a_2=Acosx[/tex]
[tex]b_1=Bsin(x+90)[/tex]
[tex]b_2=Bcos(x+90)[/tex]
Using the properties of the sum of two angles in the sin and cosine:
[tex]b_1=Bsin(x+90)=B(sinx*cos90+sin90*cosx)=Bcosx[/tex]
[tex]b_2=Bcos(x+90)=B(cosx*cos90-sinx*sin90)=-Bsinx[/tex]
Sustituying in the magnitud of the sum
[tex]C=\sqrt{(Asinx+Bcosx)^2+(Acosx-Bsinx)^2} =9[/tex]
[tex]C=\sqrt{A^2sin^2x+2ABsinxcosx+B^2cos^2x+A^2cos^2x-2ABsinxcosx+B^2sin^2x} =9[/tex]
[tex]C=\sqrt{A^2(sin^2x+cos^2x)+B^2(cos^2x+sin^2x)}[/tex]
[tex]C=\sqrt{A^2+B^2} =9[/tex]
Solving for B
[tex]A^2+B^2 =9^2[/tex]
[tex]B^2 =9^2-A^2[/tex]
Sustituying the value of the magnitud of A
[tex]B^2=81-5^2=81-25=56[/tex]
[tex]B= 7. 4833[/tex]
The calculation reveals that vector B should be approximately 7.48 in length when magnitude of A s 5.00 and magnitude of their vector sum is 9.00.
The subject question asks for the length of vector B given that it is at right angles to vector A, whose magnitude is 5.00, to ensure that the magnitude of their vector sum is 9.00. To solve this problem, we can use the Pythagorean theorem because the vectors are at right angles to each other.
Let's designate the magnitude of vector B as |B|. According to the Pythagorean theorem for right-angled triangles, we have:
|A|² + |B|² = |A + B|²
So, if |A| = 5.00 and the resultant |A + B| = 9.00, we can substitute these values to find |B|:
5.00² + |B|² = 9.00²
|B|² = 9.00² - 5.00²
|B|² = 81.00 - 25.00
|B|² = 56.00
Therefore, |B| = √(56.00)
|B| = 7.48.
So the length of B should be approximately 7.48 to get a resultant magnitude of 9.00 when added to A.
Write a cost function for the problem. Assume that the relationship is linear. Fixed cost, $410; 5 items cost $5,590 to produce. A. C(x)-1.036x + 410 ? B. C(x)= 1,036x +5,590 ? ?. ?(x) 2,072x +5,590 O D. C(x)-2,072x+410
Answer:
The required cost function is [tex]C(x)=1036x+410[/tex].
Step-by-step explanation:
It is given that the cost function represents a linear relationship.
The fixed cost is $410 and the cost of 5 items is $5,590. It means the linear function passes through the points (0,410) and (5,5590).
If a line passes through two points then the equation of line is
[tex]y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]
The equation of cost function is
[tex]y-410=\frac{5590-410}{5-0}(x-0)[/tex]
[tex]y-410=\frac{5180}{5}(x)[/tex]
[tex]y-410=36x[/tex]
[tex]y-410=1036x[/tex]
Add 410 on both the sides.
[tex]y=1036x+410[/tex]
The required cost function is
[tex]C(x)=1036x+410[/tex]
Therefore the required cost function is [tex]C(x)=1036x+410[/tex].
The required cost function is [tex]\rm C(x)= 1,036x +410[/tex].
Given
The relationship is linear.
Fixed cost, $410; 5 items cost $5,590 to produce.
What is a linear equation?An equation between two variables that gives a straight line when plotted on a graph.
The standard form represents the linear equation;
[tex]\rm y=mx+c[/tex]
The fixed cost is $410 and the cost of the 5 items is $5,590. It means the linear function passes through the points (0,410) and (5,5590).
If a line passes through two points then the equation of a line is;
[tex]\rm y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)\\\\y-410=\dfrac{5590-410}5-0}(x-0)\\\\y-410=\dfrac{5180}{5}x\\\\y-410=1036x\\\\y=1036x+410\\\\C(x)=1036x+410[/tex]
Hence, the required cost function is [tex]\rm C(x)= 1,036x +410[/tex].
To know more about the Linear equations click the link given below.
https://brainly.com/question/13275994
PLEASE HELP PRECALCULUS
WILL MARK BRAINLIEST
-SEE ATTACHMENT-
Answer:
[tex]\cos(arcsin(\frac{1}{4}))=\frac{\sqrt{15}}{4}[/tex].
Step-by-step explanation:
We want to evaluate cos(arcsin(1/4)) probably without a calculator.
If you did want a calculator answer, that would be 0.968245837.
Alright so anyways, this is the way I begin these trig(arctrig( )) types of problems when the trig parts are different.
Let u=arcsin(1/4).
If u=arcsin(1/4) then sin(u)=1/4.
So we want to find cos(u) given sin(u)=1/4. (I just replace arcsin(1/4) in cos(arcsin(1/4)) with u.)
Let's use a Pythagorean Identity:
[tex]\cos^2(u)+\sin^2(u)=1[/tex].
Let's plug in 1/4 for sin(u):
[tex]\cos^2(u)+(\frac{1}{4})^2=1[/tex]
Simplify a bit:
[tex]\cos^2(u)+\frac{1}{16}=1[/tex]
Subtract 1/16 on both sides:
[tex]\cos^2(u)=1-\frac{1}{16}[/tex]
Simplify the right hand side:
[tex]\cos^2(u)=\frac{15}{16}[/tex]
Take the square root of both sides:
[tex]\cos(u)=\pm \sqrt{\frac{15}{16}}[/tex]
Separate the square thing to the numerator and denominator:
[tex]\cos(u)=\pm \frac{\sqrt{15}}{\sqrt{16}}[/tex]
Replace [tex]\sqrt{16}[/tex] with 4 since [tex]4^2=16[/tex]:
[tex]\cos(u)=\pm \frac{\sqrt{15}}{4}[/tex]
Now how do we determine if the cosine should be positive or negative.
arcsin(1/4) is an angle that is going to be between -pi/2 and pi/2 due to restrictions upon the sine curve to be one to one.
cosine of an angle between -pi/2 and pi/2 is going to be positive because these are the 1st and 4th quadrant where the x-coordinate is positive (the cosine value is positive)
[tex]\cos(u)=\frac{\sqrt{15}}{4}[/tex]
So recall u=arcsin(1/4):
[tex]\cos(arcsin(\frac{1}{4}))=\frac{\sqrt{15}}{4}[/tex].
For fun, put [tex]\frac{\sqrt{15}}{4}[/tex]. If you don't get 0.968245837 then you made a mistake in the above reasoning. We do get that so the results of the calculator and our trigonometry/algebra confirm each other.
The graph of which function will have a maximum and a y-intercept of 4?
f(x) = 4x2 + 6x – 1
f(x) = –4x2 + 8x + 5
f(x) = –x2 + 2x + 4
f(x) = x2 + 4x – 4
Answer:
Option C (f(x) = [tex]-x^2 + 2x + 4[/tex])
Step-by-step explanation:
In this question, the first step is to write the general form of the quadratic equation, which is f(x) = [tex]ax^2 + bx + c[/tex], where a, b, and c are the arbitrary constants. There are certain characteristics of the values of a, b, and c which determine the nature of the function. If a is a positive coefficient (i.e. if a>0), then the quadratic function is a minimizing function. On the other hand, a is negative (i.e. if a<0), then the quadratic function is a maximizing function. Since the latter condition is required, therefore, the first option and the last option are incorrect. The features of the values of b are irrelevant in this question, so that will not be discussed here. The value of c is actually the y-intercept of the quadratic equation. Since the y-intercept is 4, the correct choice for this question will be Option C. In short, Option C fulfills both the criteria of the function which has a maximum and a y-intercept of 4!!!
Do the ratios 4ft./6ft. and 12sec/18sec form a proportion? Why or why not?
Answer:
Yes! There are 3 different explanations I have. Pick your favorite.
Step-by-step explanation:
So we are asked to see if the following equation holds:
[tex]\frac{4 \text{ ft }}{6 \text{ ft}}=\frac{12 \text{ sec }}{18 \text{sec}}[/tex]
The units cancel out ft/ft=1 and sec/sec=1.
So we are really just trying to see if 4/6 is equal to 12/18
Or you could cross multiply and see if the products are the same on both sides:
[tex]\frac{4}{6}=\frac{12}{18}[/tex]
Cross multiply:
[tex]4(18)=6(12)[/tex]
[tex]72=72[/tex]
Since you have the same thing on both sides then the ratios given were proportional.
OR!
Put 4/6 and 12/18 in your calculator. They both come out to have the same decimal expansion of .66666666666666666(repeating) so the ratios gives are proportional.
OR!
Reduce 12/18 and reduce 4/6 and see if the reduced fractions are same.
12/18=2/3 (I divided top and bottom by 6)
4/6=2/3 (I divided top and bottom by 2)
They are equal to the same reduced fraction so they are proportional.
Complete the square x2 – 6x + 8.
Question 3 options:
(x+3)2 – 1
(x-3)2 – 1
(x-3)2
(x-6)2 - 28
[tex]x^2-6x + 8=x^2-6x+9-1=(x-3)^2-1[/tex]
Answer:
(x - 3)^2 - 1.
Step-by-step explanation:
x2 – 6x + 8.
We divide the coefficient of x by 2:
-6 / 2 = -3 so the contents of the parentheses is x - 3:
x^2 - 6x + 8
= (x - 3)^2 - (-3)^2 + 8
= (x - 3)^2 - 1.
Calculate the area of the surface S. S is the portion of the cone (x^2/4)+(y^2/4)=(z^2/9) that lies between z=4 and z=5
Parameterize [tex]S[/tex] by
[tex]\vec r(u,v)=\dfrac23u\cos v\,\vec\imath+\dfrac23u\sin v\,\vec\jmath+u\,\vec k[/tex]
with [tex]4\le u\le5[/tex] and [tex]0\le v\le2\pi[/tex]. Take the normal vector to [tex]S[/tex] to be
[tex]\vec r_u\times\vec r_v=-\dfrac23u\cos v\,\vec\imath-\dfrac23u\sin v\,\vec\jmath+\dfrac49u\,\vec k[/tex]
(orientation doesn't matter here)
Then the area of [tex]S[/tex] is
[tex]\displaystyle\iint_S\mathrm dA=\iint_S\|\vec r_u\times\vec r_v\|\,\mathrm du\,\mathrm dv[/tex]
[tex]=\displaystyle\frac{2\sqrt{13}}9\int_0^{2\pi}\int_4^5u\,\mathrm du\,\mathrm dv[/tex]
[tex]=\displaystyle\frac{4\sqrt{13}\,\pi}9\int_4^5u\,\mathrm du=\boxed{2\sqrt{13}\,\pi}[/tex]
is picking out some movies to rent, and he has narrowed down his selections to 5 documentaries, 7 comedies, 4 mysteries, and 5 horror films. How many different combinations of 9 movies can he rent if he wants all 7 comedies?
Answer: 91
Step-by-step explanation:
Given : The number of documentaries = 5
The number of comedies = 7
The number of mysteries = 4
The number of horror films =5
The total number of movies other than comedy = 14
Now, the number of possible combinations of 9 movies can he rent if he wants all 7 comedies is given by :-
[tex]^7C_7\times^{14}C_2\\\\\dfrac{7!}{7!(7-7)!}\times\dfrac{14!}{2!(14-2)!}\\\\=(1)\times\dfrac{14\times13}{2}\\\\=91[/tex]
Therefore, the number of possible combinations of 9 movies can he rent if he wants all 7 comedies is 91 .
Last year, a person wrote 119 checks. Let the random variable x represent the number of checks he wrote in one day, and assume that it has a Poisson distribution. What is the mean number of checks written per day? What is the standard deviation? What is the variance?
Answer: The mean number of checks written per day = 0.3260
The standard deviation = 0.5710
The variance = 0.3260
Step-by-step explanation:
Given : The number of checks written by the person = 119
We assume that the year is not a leap year.
Thus, the number of days in the year must be 365.
Now, the mean number of checks written per day is given by :-
[tex]\lambda=\dfrac{119}{365}=0.3260273972\approx0.3260[/tex]
Also, in Poisson distribution , the variance is also equals to the mean value .
[tex]\text{Thus , Variance }=\sigma^2= 0.3260[/tex]
Then , [tex]\sigma= \sqrt{0.3260}=0.570964096945\approx0.5710[/tex]
Thus, Standard deviation = 0.5710
In a certain country, the true probability of a baby being a boy is 0.522. Among the next five randomly selected births in the country, what is the probability that at least one of them is a girl?
Answer: 0.9612
Step-by-step explanation:
The binomial distribution formula is given by :-
[tex]P(x)=^nC_xp^x(1-p)^{n-x}[/tex], where P(x) is the probability of x successes out of n trials, p is the probability of success on a particular trial.
Given : The probability of a baby being a boy= 0.522.
Then the probability of a girl : [tex]p=1-0.522=0.478[/tex]
Number of trials : n= 5
Now, the required probability will be :
[tex]P(x \geq1)=1-P(0)\\\\=1-[^{5}C_0(0.478)^{0}(1-0.478)^{5-0}]\\\\=1-[(1)(0.522)^{5}]=0.961242789206\approx0.9612[/tex]
Thus, the probability that at least one of them is a girl = 0.9612
The probability that at least one of them is a girl is approximately 0.9565.
Probability of At Least One Girl in Five Births
To find the probability that at least one of the next five randomly selected births in the country will be a girl, we can use the complement rule. The complement rule states that the probability of at least one girl is equal to 1 minus the probability of no girls (i.e., all boys).
Given:
→ Probability of a boy (P(B)) = 0.522
→ Probability of a girl (P(G)) = 1 - P(B)
= 1 - 0.522
= 0.478
Step-by-step calculation:
1. Calculate the probability of all five births being boys: (P(B))⁵
2. Substitute the values: (0.522)⁵
3. Calculate: (0.522)⁵ ≈ 0.0435
Therefore, the probability of all five births being boys is 0.0435.
Using the complement rule:
→ Probability of at least one girl = 1 - Probability of all boys
= 1 - 0.0435
≈ 0.9565
Thus, the probability that at least one of the next five births is a girl is approximately 0.9565.
Devin signs a note for a discounted loan agreeing to pay $2,700 in 6 months at a discount rate of 7%. Determine the amount of the discount and the proceeds to Devin.
Discount = $
Proceeds = $
Answer:
discount= $94.5
Proceeds=$2605.5
Step-by-step explanation:
amount Dawin has to pay= $2700
in 6 months time
at a discount rate of 7%
here future value = $2700
D= discount before m months is given by
[tex]D= \frac{FV\times r\times m}{1200}[/tex]
m= 6 months, r= 7% and FV= 2700
putting values
[tex]D= \frac{2700\times 7\times 6}{1200}[/tex]
solving we get
D= $94.5
now present value = future value - discount
=2700-94.5= $ 2605.5
here PV(present valve )= Proceeds= $2605.5
74% of freshmen entering public high schools in 2006 graduated with their class in 2010. A random sample of 81 freshmen is selected. Find the probability that the proportion of students who graduated is greater than 0.743 .
Answer: Probability that the proportion of students who graduated is greater than 0.743 is P = 0.4755
Step-by-step explanation:
Given that,
Probability of freshmen entering public high schools in 2006 graduated with their class in 2010, p = 0.74
Random sample of freshman, n = 81
Utilizing central limit theorem,
[tex]P(\hat{p}<p) = P(Z<\hat{p} - \frac{p}{\sqrt{\frac{p(1-p)}{n} } } )[/tex]
So,
[tex](P(\hat{p}>0.743) = P(Z>0.743 - \frac{0.74}{\sqrt{\frac{0.74(1-0.74)}{81} } } )[/tex]
= P( Z > 0.0616)
= 0.4755 ⇒ probability that the proportion of students who graduated is greater than 0.743.
Determine whether the system of linear equations has one and only one solution, infinitely many solutions, or no solution. 5/4x-2/3y=8 and 1/4x+5/3y=7
Answer:
has only one solution: [tex]x=8, y=3[/tex]
Step-by-step explanation:
[tex]\left \{ {{\frac{5x}{4} -\frac{2y}{3}=8(equation 1)} \atop {\frac{x}{4} +\frac{5y}{3} =7(equation 2)}} \right\\[/tex]
substract [tex]\frac{1}{5}[/tex]×(equation 1) from equation2
[tex]\left \{ {{\frac{5x}{4} -\frac{2y}{3}=8(equation 1)} \atop {0x +\frac{9y}{5} =\frac{27}{5}(equation 2)}} \right\\[/tex]
from equation 2 we obtain
[tex]y=\frac{27}{9} =3[/tex]
and we replace 3 in equation 1
[tex]\frac{5x}{4} -\frac{2(3)}{3} =8\\\\\frac{5x}{4} =10\\\\x=\frac{40}{5} =8[/tex]
[4] Answer the questions about the two galaxies below.
(a) Find the velocity of a galaxy if it is 8.22 Mpc away.
(b) Find the distance to a galaxy if it is moving away at a speed of 50,000 km/s.
Note: be sure to always use the formula sheet.
Answer: 592 km/s, 694 Mpc
Answer:
a) Velocity of the galaxy=573.756 km/s
b) Distance to the galaxy=716 Mpc
Step-by-step explanation:
a) [tex]v=H_0 D\\Where\ v=Velocity\ of\ the\ galaxy\\H_0= Hubble\ constant=69.8\pm 1.9\ as\ of\ 16\ July\ 2019\\D= Proper\ distance=8.22\ Mpc\\\Rightarrow v=69.8\times 8.22\\\therefore v=573.756\ km/s\\[/tex]
b)[tex]v=H_0 D\\v=50000\ km/s\\H_0= Hubble\ constant=69.8\pm 1.9\\\Rightarrow D=\frac{v}{H_0}\\\Rightarrow D=\frac{50000}{69.8}\\\therefore D=716\ Mpc[/tex]
Compute Lenny's estimated tax payment for the third quarter. He is self-employed and he expects to earn $40,800.00 this year. His estimated income tax rate is 19%.
Answer:
Lenny's tax payment for the year will be $7,752
(The third quarter payment would be $1,938)
Step-by-step explanation:
Hello, great question. These types are questions are the beginning steps for learning more advanced Problems.
Taxes are calculated once a year based on your yearly income. That being said we can look at Lenny's income for the year ($40,800) and multiply that by 0.19 (19%) to calculate his tax payment for the year.
[tex]$40,800 * 0.19 = $7,752[/tex]
So Lenny's tax payment for the year will be $7,752 . The question asks for payment for the third quarter but as mentioned above tax is calculated yearly.
That being said if you would like to know how much it would be quarterly we can simply divide the tax payment by 4.
[tex]7,752 / 4 = 1,938[/tex]
So the third quarter payment would be $1,938
I hope this answered your question. If you have any more questions feel free to ask away at Brainly.