Answer:
False
Step-by-step explanation:
If two spheres have the same center but different radii, they are NOT called concentric spheres. They would be called congruent circles if they have the same center but different radii.
Answer:
false
Step-by-step explanation:
what is the y intercept for f(x) = 5x +7
Answer:
7
Step-by-step explanation:
the slope intercept form is y=mx + b
where b is the y intercept,
and your question is y=5x + 7
so the y intercept form would equal to 7
What are the slope and y-intercept of the linear function graphed to the left?
Answer:
y intercept equals 1
Step-by-step explanation:
y= -1/2x+1
the slope is -1/2
the y intercept is 1
which methods could you use to calculate the y-coordinate of the midpoint of a vertical line segment with endpoints at (0,0) and (0,15)
Answer:
Option D. Divide 15 by 2
Step-by-step explanation:
we know that
To find the y-coordinate of the midpoint of a vertical line, adds the y-coordinates of the endpoints and divide by two
we have the endpoints
(0,0) and (0,15)
The y-coordinate of the midpoint is (0+15)/2=15/2=7.5
therefore
Divide 15 by 2
Answer:
the answer is to count by hands ( A ) and divide 15 by 2 ( D )
Step-by-step explanation:
Choose a number between and that is a multiple 45 of and 95 . Write all the numbers that she could choose. If there is more than one number, separate them with commas.
Answer with explanation:
To find the common multiple of 45 and 95,we will find HCF of 45 and 95.
45=3 × 3× 5
95=5 × 19
⇒H CF(45,95)
=3 × 3×5×19
=855
→Common multiple of 45 and 95 =855
→There are infinite number of multiple of 855 which are 855, 1710, 2565,.....
You have not written between which two numbers.So, you should write multiple of 855 such that it is smaller than the greater number.
Find the distance between the points (0, –1) and (3, –3).
A. 25
B. 5
C. √13
D. 13
Answer:
C. √13
Step-by-step explanation:
The distance between two points is given by
d =sqrt( (x2-x1)^2 + (y2-y1)^2)
= sqrt( (3-0)^2 + (-3--1)^2)
= sqrt( 3^2 + (-3+1)^2)
= sqrt( 9+(-2)^2)
= sqrt( 9+4)
= sqrt(13)
To answer this, you basically use Pythagoras' Theroem, but instead of:
[tex]c = \sqrt{a^{2} + b^{2}}[/tex]
it will be :
[tex]distance = \sqrt{(y - y1)^{2} + (x - x1)^{2} }[/tex]
So you are finding the squareroot of the (difference in y coordinates)² plus (difference in x coordinates) ²:
x is the x-coordinate of (0, -1) (so x = 0)
y is the y-coordinte of (0, -1) ( so y = -1)
x1 is the x coordinate of (3, -3) ( so x1 = 3)
y1 is the y coordinate of (3, -3) (so y1 = -3)
--------------------------------------------------
Now, lets find the distance between the two points, by substituting all of this values into the equation at the top:
[tex]distance = \sqrt{(y - y1)^{2} + (x - x1)^{2} }[/tex] (substitute in values)
[tex]distance = \sqrt{( 0 -3)^{2} + (-1 - -3)^{2} }[/tex] (simplify: note -1 - - 3 = -1 + 3)
[tex]distance = \sqrt{( -3)^{2} + (-1 +3)^{2} }[/tex] (simplify)
[tex]distance = \sqrt{( -3)^{2} + (2)^{2} }[/tex] (now square the numbers)
[tex]distance = \sqrt{9 + 4 }[/tex] (simplify)
[tex]distance = \sqrt{13 }[/tex]
___________________________________________
Answer:C. [tex]\sqrt{13}[/tex]
Tyler and Katie started a lemonade stand to raise money. They donated \dfrac{2}{10} 10 2 ? start fraction, 2, divided by, 10, end fraction of their profits to their school library, \dfrac{1}{10} 10 1 ? start fraction, 1, divided by, 10, end fraction to the animal shelter, and \dfrac{4}{10} 10 4 ? start fraction, 4, divided by, 10, end fraction to the food bank. They saved the rest to buy materials for their next project. What fraction of their profits did Tyler and Katie donate?
Answer:
[tex]\frac{7}{10}[/tex]
Step-by-step explanation:
Fraction of the amount donated to school library = [tex]\frac{2}{10}[/tex]
Fraction of the amount donated to animal shelter = [tex]\frac{1}{10}[/tex]
Fraction of the amount donated to food bank = [tex]\frac{4}{10}[/tex]
The rest of the amount was saved for next project.
Thus, the total fraction of the amount donated will be the sum of fractions of amount donated to school library, animal shelter and food bank.
i.e.
Fraction of the amount donated = [tex]\frac{2}{10}+\frac{1}{10}+\frac{4}{10} = \frac{7}{10}[/tex]
This means, Tyler and Katie donated [tex]\frac{7}{10}[/tex] of their profits.
Answer:−1.825
Step-by-step explanation:
The variable z is inversely proportional to x. When x is 6, z has the value of 2. What is the value of z when x=13
Round to at least the thousandths place if needed
Answer:
[tex]z=0.923[/tex]
Step-by-step explanation:
we know that
A relationship between two variables, x, and z, represent an inverse variation if it can be expressed in the form [tex]z*x=k[/tex] or [tex]z=k/x[/tex]
step 1
Find the value of k
For x=6, z=2
[tex]z*x=k[/tex]
substitute
[tex]2*6=k[/tex]
[tex]k=12[/tex]
therefore
The equation of the inverse variation is equal to
[tex]z*x=12[/tex]
step 2
What is the value of z when x=13
substitute the value of x in the equation and solve for z
[tex]z*(13)=12[/tex]
[tex]z=12/13[/tex]
[tex]z=0.923[/tex]
Please help prove these identities!
We have the following expression:
[tex]tan(\theta)cot(\theta)-sin^{2}(\theta)=cos^2(\theta)[/tex]
We know that:
[tex]cot(\theta)=\frac{1}{cot(\theta)}[/tex]
Therefore, by substituting in the original expression:
[tex]tan(\theta)\left(\frac{1}{tan(\theta)}\right)-sin^{2}(\theta)=cos^2(\theta) \\ \\ \\ Simplifying: \\ \\ 1-sin^2(\theta)=cos^2(\theta)[/tex]
We know that the basic relationship between the sine and the cosine determined by the Pythagorean identity, so:
[tex]sin^2(\theta)+cos^2(\theta)=1[/tex]
By subtracting [tex]sin^2(\theta)[/tex] from both sides, we get:
[tex]\boxed{cos^2(\theta)=1-sin^2(\theta)} \ Proved![/tex]
PART b)We have the following expression:
[tex]\frac{cos(\alpha)}{cos(\alpha)-sin(\alpha)}=\frac{1}{1-tan(\alpha)}[/tex]
Here, let's multiply each side by [tex]cos(\alpha)-sin(\alpha)[/tex]:
[tex](cos(\alpha)-sin(\alpha))\left(\frac{cos(\alpha)}{cos(\alpha)-sin(\alpha)}\right)=(cos(\alpha)-sin(\alpha))\left(\frac{1}{1-tan(\alpha)}\right) \\ \\ Then: \\ \\ cos(\alpha)=\frac{cos(\alpha)-sin(\alpha)}{1-tan(\alpha)}[/tex]
We also know that:
[tex]tan(\alpha)=\frac{sin(\alpha)}{cos(\alpha)}[/tex]
Then:
[tex]cos(\alpha)=\frac{cos(\alpha)-sin(\alpha)}{1-\frac{sin(\alpha)}{cos(\alpha)}} \\ \\ \\ Simplifying: \\ \\ cos(\alpha)=\frac{cos(\alpha)-sin(\alpha)}{\frac{cos(\alpha)-sin(\alpha)}{cos(\alpha)}} \\ \\ Or: \\ \\ cos(\alpha)=\frac{\frac{cos(\alpha)-sin(\alpha)}{1}}{\frac{cos(\alpha)-sin(\alpha)}{cos(\alpha)}} \\ \\ Then: \\ \\ cos(\alpha)=cos(\alpha).\frac{cos(\alpha)-sin(\alpha)}{cos(\alpha)-sin(\alpha)} \\ \\ \boxed{cos(\alpha)=cos(\alpha)} \ Proved![/tex]
PART c)We have the following expression:
[tex]\frac{cos(x+y)}{cosxsiny}=coty-tanx[/tex]
From Angle Sum Property, we know that:
[tex]cos(x+y)=cos(x)cos(y)-sin(x)sin(y)[/tex]
Substituting this in our original expression, we have:
[tex]\frac{cos(x)cos(y)-sin(x)sin(y)}{cosxsiny}=coty-tanx[/tex]
But we can also write this as follows:
[tex]\\ \frac{cosxcosy}{cosxsiny}-\frac{sinxsiny}{cosxsiny}=coty-tanx \\ \\ Simplifying: \\ \\ \frac{cosy}{siny}-\frac{sinx}{cosx} =coty-tanx \\ \\ But: \\ \\ \frac{cosy}{siny}=coty \\ \\ \frac{sinx}{cosx}=tanx \\ \\ Hence: \\ \\ \boxed{coty-tanx=coty-tanx} \ Proved![/tex]
PART d)We have the following expression:
[tex]\ln\left|1+cos \theta\right|+\ln\left|1-cos \theta\right|=2\ln\left|sin \theta\right|[/tex]
By Logarithm product rule, we know:
[tex]log_{b}(x.y) = log_{b}(x) + log_{b}(y)[/tex]
So:
[tex]\ln\left|1+cos \theta\right|+\ln\left|1-cos \theta\right|=\ln\left|(1+cos \theta)(1-cos \theta)\right|[/tex]
The Difference of Squares states that:
[tex]a^2-b^2=(a+b)(a-b) \\ \\ So: \\ \\ (1+cos \theta)(1-cos \theta)=1-cos^2 \theta[/tex]
Then:
[tex]\ln\left|(1+cos \theta)(1-cos \theta)\right|=\ln\left|1-cos^{2} \theta\right|[/tex]
By the Pythagorean identity:
[tex]sin^2(\theta)+cos^2(\theta)=1 \\ \\ So: \\ \\ sin^2 \theta = 1-cos^2 \theta[/tex]
Then:
[tex]\ln\left|1-cos^{2} \theta\right|=\ln\left|sin^2 \theta|[/tex]
By Logarithm power rule, we know:
[tex]log_{b}(x.y) = ylog_{b}(x)[/tex]
Then:
[tex]\ln\left|sin^2 \theta|=2\ln\left|sin \theta|[/tex]
In conclusion:
[tex]\boxed{\ln\left|1+cos \theta\right|+\ln\left|1-cos \theta\right|=2\ln\left|sin \theta\right|} \ Proved![/tex]
Cosella is conducting an experiment where she assesses how quickly teenagers can run a 100-meter race after consuming specific amounts of caffeine. She divides her sample up into three groups. Group 1 receives a glass of water with no caffeine added. Group 2 receives a glass of water with an amount of caffeine equivalent to that in one cup of coffee. Group 3 receives a glass of water with an amount of caffeine equivalent to that in two cups of coffee. Each participant is then timed as they run the course. In this study, the independent variable is
a. the previous running experience of each participant
b. the teenagers who are being studied
c. the time it takes to run the 100-meter race
d. the amount of caffeine being ingested
Answer:
c. the time it takes to run the 100-meter race
Step-by-step explanation:
An independent variable is the variable which is not being controlled and it does not depend on the other variables. This is the variable which is being studied/measured in the experiment.
Option a. The previous running experience is not being considered and is not a variable under study in this case. So this is not the answer.
Option b. The teenagers who are being studied constitute the sample. These are not the variables.
Option c. Time is the independent variable, as it is being measured during the experiment and the conclusion is being drawn based on it.
Option d. Amount of caffeine is being decided by Cosella and is therefore not the independent variable.
Therefore, the correct answer is option c
help your girl out !!
giving out 15 points plus brainliest
Write the contrapositive of the conditional statement. Determine whether the contrapositive is true or false. If it is false, find a counterexample. If you have a gerbil, then you are a pet owner
Answer: The contrapositive statement :"If you do not have a gerbil, then you are not a pet owner.”
It is false.
Counter example : If you have a dog, then you are a pet owner.
Step-by-step explanation:
We know that the contrapositive of a statement of the form " If a then b" is "If not a then not b.
Given: The conditional statement is "If you have a gerbil, then you are a pet owner.”
Then the contrapositive statement will be "If you do not have a gerbil, then you are not a pet owner.”
The contrapositive statement is false.
Counter example : If you have a dog, then you are a pet owner.
Means if you area pet owner then it can be any pet not just gerbil.
Answer:
The contrapositive is false.
Step-by-step explanation:
Given conditional statement is :
If you have a gerbil, then you are a pet owner (conditional statement is in the form of if p, then q)
The contrapositive is represented as (if not q, then not p)
So, the contrapositive sentence will be :
If you are not a pet owner, then you do not have a gebril.
This statement is false as if you are not a pet owner then you will not have any animal with you and not only gebril.
An engineer is going to redesign an ejection seat for an airplane. the seat was designed for pilots weighing between 130lb and 171lb. The new population of pilots has normally distributed weights with a mean of 137lb and a standard deviation of 28.9lb. If a pilot is randomly selected find the probability that his weight is between 130lb and 171lb
Answer: 0.4758
Step-by-step explanation:
Given : Mean : [tex]\mu=137\text{ lb}[/tex]
Standard deviation : [tex]\sigma =28.9\text{ lb}[/tex]
Also, the new population of pilots has normally distributed .
The formula to calculate the z-score :-
[tex]z=\dfrac{x-\mu}{\sigma}[/tex]
For x=130 lb .
[tex]z=\dfrac{130-137}{28.9}=-0.2422145\approx-0.24[/tex]
For x=171lb.
[tex]z=\dfrac{171-137}{28.9}=1.1764705\approx1.18[/tex]
The p-value =[tex]P(-0.24<z<1.18)=P(z<1.18)-P(z<-0.24)[/tex]
[tex]=0.8809999-0.4051651=0.4758348\approx0.4758348\approx0.4758[/tex]
Hence, the required probability : 0.4758
Find the slope of the function f ( x ) = 5x/2 + 3, by the definition of limit. Express answer as a fraction using the "/" key as the fraction bar.
[tex]\huge{\boxed{\frac{5}{2}}}[/tex]
Slope-intercept form is [tex]f(x)=mx+b[/tex], where [tex]m[/tex] is the slope and [tex]b[/tex] is the y-intercept.
[tex]\frac{5x}{2}=\frac{5}{2}x[/tex], so change the equation to represent this. [tex]f(x)=\frac{5}{2}x+3[/tex]
Great! Now the function is in slope-intercept form, so we can just see that [tex]m[/tex], or the slope, is equal to [tex]\boxed{\frac{5}{2}}[/tex]
There are two newborns, Gary and Eric. The future lifetime of Gary is uniformly distributed between 0 to 60 years. The future lifetime of Eric is uniformly distributed between 0 to 40 years. Their future lifetimes are independent. Calculate the probability that Gary dies first.
Answer: 0.25
Step-by-step explanation:
Given : The future lifetime of Gary is uniformly distributed with interval [0 years , 60 years].
Then the probability density function for Gary's future lifetime will be:-
[tex]f(x)=\dfrac{1}{60-0}=\dfrac{1}{60}[/tex]
The future lifetime of Eric is uniformly distributed with interval [0 years , 40 years].
Then the probability density function for Erin's future lifetime will be:-
[tex]f(x)=\dfrac{1}{40-0}=\dfrac{1}{40}[/tex]
Now, the joint density function for Gary and Eric's future lifetime :-
[tex]f(x,y)=f(x)f(y)=\dfrac{1}{40\times60}=\dfrac{1}{2400}[/tex] [∵Their future lifetimes are independent. ]
Now, the probability that Gary dies first is given by :-
[tex]\int^{60}_{0}\int^{40}_{x}f(x,y)\ dy\ dx\\\\=\int^{60}_{0}\int^{40}_{x}\dfrac{1}{2400}\ dy\ dx\\\\=\int^{60}_{0}\dfrac{40-x}{2400}\ dx\\\\=\dfrac{1}{2400}[40x-\dfrac{x^2}{2}]^{60}_{0}\\\\=\dfrac{1}{2400}(2400-\dfrac{3600}{2})=0.25[/tex]
Hence, the probability that Gary dies first =0.25
Please help me. these problems
Answer:
1st problem:
Converges to 6
2nd problem:
Converges to 504
Step-by-step explanation:
You are comparing to [tex]\sum_{k=1}^{\infty} a_1(r)^{k-1}[/tex]
You want the ratio r to be between -1 and 1.
Both of these problem are so that means they both have a sum and the series converges to that sum.
The formula for computing a geometric series in our form is [tex]\frac{a_1}{1-r}[/tex] where [tex]a_1[/tex] is the first term.
The first term of your first series is 3 so your answer will be given by:
[tex]\frac{a_1}{1-r}=\frac{3}{1-\frac{1}{2}}=\frac{3}{\frac{1}{2}=6[/tex]
The second series has r=1/6 and a_1=420 giving me:
[tex]\frac{420}{1-\frac{1}{6}}=\frac{420}{\frac{5}{6}}=420(\frac{6}{5})=504[/tex].
Can someone please help me with this math question
Answer:
C'(4,4)
Step-by-step explanation:
The dilation of quadrilateral ABCD over the origin by a scale factor of 2 has the rule
(x,y)→(2x,2y)
So,
A(-3,-1)→A'(-6,-2)B(-1,1)→B'(-2,2)C(2,2)→C'(4,4)D(3,-2)→D'(6,-4)Hence, the coordinates of the image point C' are (4,4) (see attached diagram for details)
Answer:
The coordinates of C' = (4,4)
Step-by-step explanation:
The coordinates of C can be found by looking at the graph,
Coordinates of C = (2,2)
ABCD is dilated by a factor of 2 to get A'B'C'D'.
So, the coordinates of C' will be found by multiplying the coordinates of C by 2.
C' = (2*2,2*2)
C' = (4,4)
So, The coordinates of C' = (4,4)
In triangle ABC AD/DB = CE/EB. Complete the proof showing the segment DE is parallel to segment AC.
1.
a) (AD/DB) + 1 = (CE/EB) + 1
b) (AD/DB) + DE = (CE/EB) + DE
c) AD * EB = CE * DB
2.
a) Corresponding sides of congruent triangles are congruent.
b) Addition Property of Equality
c) cross multiplication
Edit: Answer is 1.A and 2.B (verified correct) thanks to
https://brainly.com/question/1428177
Answer:
1. [tex]\dfrac{AD}{DB}+1=\dfrac{CE}{EB}+1[/tex]
2. Addition property of equality
Step-by-step explanation:
In triangle ABC,
[tex]\dfrac{AD}{DB}=\dfrac{CE}{EB}.[/tex]
The addition property of equality states that if the same amount is added to both sides of an equation, then the equality is still true.
Use addition property of equality, add 1 to both sides of previouse equality:
[tex]\dfrac{AD}{DB}=\dfrac{CE}{EB}\\ \\\dfrac{AD}{DB}+1=\dfrac{CE}{EB}+1\\ \\\dfrac{AD+DB}{DB}=\dfrac{CE+EB}{EB}[/tex]
Answer:
(AD/DB) +1 = (CE/EB) +1 -----> Addition Property of Equality
If 10 were added to each of the values in a data set that originally had a standard deviation of 6, the standard deviation of the resulting data would be 6 true false
Answer:
TRUE
Step-by-step explanation:
Changing the mean by adding the same number to every data value does not change the differences those values have from the new mean. Hence the standard deviation remains unchanged. If it was 6, it will be 6.
Answer:
True because standard divination stays the same
Step-by-step explanation:
What is the complementary event to drawing a blue marble? (check all that apply)
drawing a red marble
drawing a green marble
drawing a red or green marble
not drawing a blue marble
PLZ hurry I give brainly
The complementary event to drawing a blue marble includes any outcome other than drawing a blue marble. Therefore, drawing a red marble, a green marble, a red or green marble, or not drawing a blue marble, all are complementary events.
Explanation:In probability, the complementary event of an event represents all outcomes not covered by the original event. In this case, the original event is 'drawing a blue marble'. Thus, the complementary event would include any outcome other than drawing a blue marble.
Based on the options given:
Drawing a red marbleDrawing a green marbleDrawing a red or green marbleNot drawing a blue marbleAll these are complementary events to drawing a blue marble, as they all represent outcomes other than 'drawing a blue marble'.
Learn more about Probability here:https://brainly.com/question/32117953
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A rectangle's width is one-fourth of its length. Its area is 9 square units. The equation l(l) = 9 can be used to find l, the length of the rectangle. What is the length of the rectangle? 0.75 units 1.5 units 3 units 6 units
Answer:
6 units
Step-by-step explanation:
A rectangle's width is one-fourth of its length.
w = 1/4 l
area is 9 square units
A = l*w = 9
Replacing w with 1/4l
l * (1/4l) = 9
1/4 l^2 = 9
Multiply each side by 4 to clear the fraction
4 * 1/4 l^2 = 4*9
l^2 = 36
Take the square root of each side
sqrt (l^2) = sqrt(36)
l =6
Answer:
6 units
Step-by-step explanation:
Let the length = L
Then the width = L/4
area = length * width
area = L * L/4 = 9
L^2/4 = 9
L^2 = 36
L = 6 or L = -6
Since we are dealing with a length, we eliminate the negative answer.
Answer: 6 units
P.S. Your equation is incorrect. L(L) = 9 would work for a square with 4 congruent sides and area 9. Here the sides have different lengths. The equation is L(L/4) = 9.
CAN SOMEONE HELP ME FIND THE CIRCUMFERENCE
Answer:
51.496 miles
Step-by-step explanation:
circumference of circle= 2pir
here we will tale radius as 8.2 because 16.4 is diameter of circle.
2*3.14*8.2=
6.28*8.2=51.496 miles
You have a 10 by 24 piece of cardboard. You are going to cut squares of equal size from each corner, and fold up the sides to make an open box as shown below. Write an expression for the width of the box.
Answer:
10-2x
Step-by-step explanation:
If x is the length of one side of the square, the total width of the cardboard has two squares cut from it. The amount of width remaining is the width of the box. Since the original width of the cardboard is 10, the width of the box is ...
10 -2x
What is the slope of the line with equation y-3=-1/2(x-2)
Answer:
[tex]m =-\frac{1}{2}[/tex]
Step-by-step explanation:
The equation of a line in the pending intersection form is:
[tex]y = mx + b[/tex]
Where m is the slope of the line and b is the intersection with the y axis.
In this case we have the following equation
[tex]y-3=-\frac{1}{2}(x-2)[/tex]
To find the slope of this line you must rewrite it in the form
[tex]y = mx + b[/tex]
Then we solve the equation for y.
[tex]y-3=-\frac{1}{2}(x-2)[/tex]
[tex]y=-\frac{1}{2}(x-2)+3[/tex]
[tex]y=-\frac{1}{2}x-2*(-\frac{1}{2})+3[/tex]
[tex]y=-\frac{1}{2}x+1+3[/tex]
[tex]y=-\frac{1}{2}x+4[/tex]
Note that [tex]m =-\frac{1}{2}[/tex]
Finally the slope is: [tex]m =-\frac{1}{2}[/tex]
The slope of the line with equation; y-3 = -1/2(x-2) is; slope, m = -1/2.
According to the question, the equation of the line in discuss is; y-3 = -1/2(x-2).
To determine the slope of the line, we need to rearrange the equation such that it resembles the slope-intercept form of the equation of a straight line as follows;
The equation of a straight line; y = mx + c.
Now, we expand the equation of the line and rearrange as follows;
y-3 = (-1/2)x -1y = (-1/2)x -1 + 3y = (-1/2)x + 2.By comparison, the slope of the line given bey the equation, y-3=-1/2(x-2) is; slope, m = -1/2.
Read more:
https://brainly.com/question/19088520
What is the measure of x? Help me on this Geometry question.
Answer:
21°
Step-by-step explanation:
the angles of triangle abc has to = 180 so subtract the known angles to get 21
angles bca and daf have to be the same so its 21
Answer:
[tex]x=21[/tex]
Step-by-step explanation:
We have been given an image of two parallel lines cut by a transversal. We are asked to find the measure of x.
We know that corresponding angles of two parallel lines are equal. We can see that angle BCA and angle DAF are corresponding angles.
Let us find measure of angle BCA using angle sum property.
[tex]54^{\circ}+105^{\circ}+m\angle BCA=180^{\circ}[/tex]
[tex]159^{\circ}+m\angle BCA=180^{\circ}[/tex]
[tex]159^{\circ}-159^{\circ}+m\angle BCA=180^{\circ}-159^{\circ}[/tex]
[tex]m\angle BCA=21^{\circ}[/tex]
Therefore, the value of x is 21 degrees.
When visiting his parents, Tyler drives at an average speed of 42 km/h through urban areas and at an average speed of 105 km/h on the motorway. His journey usually takes him 2.5 hours. One day when there is fog, he sets off 1 hour early and only manages to drive at an average speed of 28 km/h in the urban areas and 60 km/h on the motorway. He arrives 30 minutes late. What was the total distance that Tyler travelled?
Answer:
168 km
Step-by-step explanation:
Let x represent the distance Tyler drives at the slower speed, and let y represent the distance at the higher speed. Using time = distance/speed, we can write equations for the total travel time:
x/42 +y/105 = 2.5
x/28 +y/60 = 4.0 . . . . . 1.5 hours more than the usual 2.5 hours
Multiplying the first equation by 210, we have ...
5x +2y = 525
Multiplying the second equation by 420, we get ...
15x +7y = 1680
Subtracting 3 times the first of these equations from the second, we have ...
(15x +7y) -3(5x +2y) = (1680) -3(525)
y = 105
Putting this into the very first equation, we get ...
x/42 + 105/105 = 2.5
x/42 = 1.5 . . . . . . subtract 1
x = 63 . . . . . . . . .multiply by 42.
The total distance to Tyler's parents' house is ...
63 km + 105 km = 168 km
Tyler's total travel distance is approximately 168 km.
Calculating Total Distance Traveled
To determine the total distance Tyler traveled, let du be the distance through urban areas and dm be the distance on the motorway.
→ The total distance is:
[tex]D = d_u + d_m[/tex]
First, using the normal journey:
→ Urban Area:
Speed = 42 km/h
Time = [tex]t_u[/tex] / 42,
→ Motorway:
Speed = 105 km/h
Time = [tex]t_m[/tex] / 105,
→ Total time for normal journey:
→ [tex]t_u/42 + t_m/105 = 2.5\ hours[/tex]
We have:
→ [tex]d_u[/tex] = 42 * [tex]t_u[/tex]
→ [tex]d_m[/tex] = 105 * [tex]t_m[/tex]
When there is fog:
→ Urban Area:
Speed = 28 km/h
Time = [tex]t__uf}[/tex] / 28
→ Motorway:
Speed = 60 km/h
Time = [tex]t_{um[/tex] / 60
Total time for foggy journey:
→ [tex]t_{uf[/tex] /28 + [tex]t_{mf[/tex] /60
Given that he leaves 1 hour early and arrives 30 minutes late, the total journey time in foggy conditions is:
→ 2.5+1+0.5=4 hours
Thus,
→ [tex]t_{uf[/tex] /28 + [tex]t_{mf[/tex] /60 = 4
Solving the Equations
We now have two equations:
→ [tex]t_u/42 + t_m/105 = 2.5\ hours[/tex]
→ [tex]t_{uf}\ /\ 28\ + t_{mf} \ /\ 60 = 4 hours[/tex]
Let's solve these equations step-by-step.
First, let's multiply the first equation by 210 (the least common multiple of 42 and 105):
→ [tex]210(t_u/42 + t_m/105) = 210*2.5[/tex]
→ [tex]5t_u+2t_m=525[/tex] (eq. 1)
Next, let's multiply the second equation by 420 (the least common multiple of 28 and 60):
→ [tex]420( t_u/28+ t_m /60)=420*4[/tex]
→ [tex]15t_u +7t_m =1680[/tex] (eq. 2)
We now solve these two linear equations:
→ [tex]5t_u+2t_m=525[/tex]
→ [tex]15t_u +7t_m =1680[/tex]
First, let's solve Equation 1 for [tex]t_m[/tex] in terms of [tex]t_u[/tex]:
→ [tex]d_m=(525-5d_u)/2[/tex]
Substitute this expression into Equation 2:
→ [tex]15t_u+7((525-5d_u)/2)=1680[/tex]
Multiply through by 2 to clear the fraction:
→ [tex]30t_u +7(525-5t_u )=3360[/tex]
→ [tex]30t_u +3675-35t_u =3360[/tex]
→ [tex]-5t_ u +3675=3360[/tex]
→ [tex]-5t_u=3360-3675[/tex]
→ [tex]-5t _u=-315[/tex]
→ [tex]t_u=63[/tex]
Now substitute [tex]t_u=63[/tex] back into Equation 1 to find [tex]t_m[/tex]:
→ [tex]5(63)+2t_m =525[/tex]
→ [tex]315+2t_m =525[/tex]
→ [tex]2t_m =210[/tex]
→ [tex]t_m=105[/tex]
Thus, the total distance Tyler travels is:
[tex]= t _u +t_m[/tex]
[tex]=63+105[/tex]
[tex]=168\ kilometers[/tex]
What is cos3phi= 1/2??? Please help and explain!
Answer:
[tex]\large\boxed{\Phi=\dfrac{\pi}{9}+\dfrac{2k\pi}{3}\ or\ \Phi=-\dfrac{\pi}{9}+\dfrac{2k\pi}{3}}[/tex]
Step-by-step explanation:
[tex]\cos3\Phi=\dfrac{1}{2}\qquad\text{substitute}\ 3\Phi=\theta\\\\\cos\theta=\dfrac{1}{2}\iff\theta=\dfrac{\pi}{3}+2k\pi\ or\ \theta=-\dfrac{\pi}{3}+2k\pi\qquad k\in\mathbb{Z}\\\\\text{We're going back to substitution:}\\\\3\Phi=\dfrac{\pi}{3}+2k\pi\ or\ 3\Phi=-\dfrac{\pi}{3}+2k\pi\qquad\text{divide both sides by 3}\\\\\Phi=\dfrac{\pi}{9}+\dfrac{2k\pi}{3}\ or\ \Phi=-\dfrac{\pi}{9}+\dfrac{2k\pi}{3}[/tex]
Eggs ares sold in boxes. A small box holds 6 eggs hina buys x small boxes of eggs write down in terms of x the total number of eggs in these small boxes
[tex]6x[/tex]
............................................
A Chi square test has been conducted to assess the relationship between marital status and church attendance. The obtained Chi square is 23.45 and the critical Chi square is 9.488. What may be concluded?
a. reject the null hypothesis, church attendance and marital status are dependent
b. reject the null hypothesis, church attendance and marital status are independent
c. fail to reject the null hypothesis, church attendance and marital status are dependent
d. fail to reject the null hypothesis, church attendance and marital status are independent
Answer: a. reject the null hypothesis, church attendance and marital status are dependent
Step-by-step explanation:
If the obtained chi-square value is greater than the critical chi square value then we reject the null hypothesis.Given : A Chi square test has been conducted to assess the relationship between marital status and church attendance. The obtained Chi square is 23.45 and the critical Chi square is 9.488.
Null hypothesis : There is no relationship between the variables.
Alternative hypothesis : There is a relationship between the variables.
Here we can see that the obtained chi-square (23.45) value is greater than the critical chi square value (9.488) , then we have to reject the null hypothesis.
So the correct answer is reject the null hypothesis, church attendance and marital status are dependent.
Given the obtained Chi-square 23.45 is greater than the critical Chi square 9.488, we reject the null hypothesis, implying there is a significant relation or dependence between marital status and church attendance.
Explanation:In a Chi square test, if the obtained Chi square value is higher than the critical Chi square value, it means that the observed data significantly deviates from what is expected under the null hypothesis. Therefore, in this case, where the obtained Chi square is 23.45 and the critical number is 9.488, we would reject the null hypothesis. Considering that the null hypothesis is generally posed under the assumption of no relation or independence between the variables being tested, rejecting it thus implies that there is a significant relationship or dependence between marital status and church attendance. Therefore, the correct answer to the question is a. reject the null hypothesis, church attendance and marital status are dependent
.
Learn more about Chi square test here:https://brainly.com/question/30696573
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Santi buys 2 t-shirts for $9.50 each, a 3-pack of socks for $7.95, and a pair of shoes for $49.95. The sales tax is 6. To the nearest cent, what is the total cost of Santi's purchases?
Answer:
$98.47
Step-by-step explanation:
1. 2(9.5) + 3 (7.95) + 49.95 = $92.80
6% • $92.80 = $5.57
$92.80 + $5.57 = $98.47
Find all polar coordinates of point P where P = ordered pair 1 comma pi divided by 3.
Answer:
(1, π/3 +2kπ), (-1, 4π/3 +2kπ) . . . where k is any integer
Step-by-step explanation:
Adding any multiple of 2π to the angle results in the same point in polar coordinates.
Adding 180° (π radians) to the point effectively negates the magnitude. As above, adding any multiple of 2π to this representation is also the same point in polar coordinates.
There are an infinite number of ways the coordinates can be written.
Answer:
All the polar coordinates of point P are [tex](1,2n\pi+\frac{\pi}{3})[/tex] and [tex](-1,(2n+1)\pi+\frac{\pi}{3})[/tex], where n is an integer.
Step-by-step explanation:
The given point is
[tex]P=(1,\frac{\pi}{3})[/tex] .... (1)
If a point is defined as
[tex]P=(r,\theta)[/tex] .... (2)
then the polar coordinates of point P is defined as
[tex](r,\theta)=(r,2n\pi+\theta)[/tex]
[tex](r,\theta)=(-r,(2n+1)\pi+\theta)[/tex]
where, n is an integer and θ is in radian.
From (1) and (2) we get
[tex]r=1, \theta=\frac{\pi}{3}[/tex]
So, the polar coordinates of point P are
[tex](r,\theta)=(1,2n\pi+\frac{\pi}{3})[/tex]
[tex](r,\theta)=(-1,(2n+1)\pi+\frac{\pi}{3})[/tex]
Therefore all the polar coordinates of point P are [tex](1,2n\pi+\frac{\pi}{3})[/tex] and [tex](-1,(2n+1)\pi+\frac{\pi}{3})[/tex], where n is an integer.