A triangle has side lengths 4, 7 and 9. What is the measure of the angle across from the longest side?
92 = 42 + 72 − 2g4g7cos(A)
81 = 16 + 49 − 56cos(A)
81 = 9cos(A)
9 = cos(A)
A cannot exist!
Gabe tried to use the law of cosines to find an unknown angle measure in a triangle. His work is shown. What is Gabe’s error?
Gabe reversed the order of the 9 and the 4.
Gabe squared the numbers incorrectly.
Gabe should not have subtracted 56 from
16 + 49.
Gabe incorrectly stated that cos–1(9) is not defined.
Answers
Gabe should not have subtracted 56 from 16+49.
_____
Rather, Gabe should have subtracted 16+49 from 81 to get
16 = -56cos(A)
cos(A) = -16/56 = -2/7
A = arccos(-2/7) ≈ 106.6°
Answer:
Step-by-step explanation:
Given that a triangle has sides 4,7 and 9
A student Gabe tried to use law of cosines to find unknown angle measure
The angle is opposite side 9 because angle across the longest side is given
He used cosine formula for triangles
[tex]a^2=b^2+c^2-2bccosA\\9^2 = 4^2+7^2-2(4)(8) cosA\\81-65 =-56 cosA\\[/tex]
But instead he adjusted -56 with 16 +49 which is wrong
Because -56 has product as cosA it is not like term as other constants
So correct step should be
81 = 65-56 Cos A
Gabe should not have subtracted 56 from
16 + 49.
This is the correct answer
Related Questions
Good Treads and Speed Tracks manufacture tires. Good Treads claims that their tires last longer than Speed Tracks tires. A car company decided to test Good Tread's claim. They purchased 20 sets of Good Tread's tires and 20 sets of Speed Track's tires. They tested the lifetime of each tire by simulating 1,000 miles of driving conditions for each set of tires each day. At the end of each day, they measured the tread on each of the tires. Once the tire tread drops below minimum safe tread depth, the tire is considered to have passed its lifetime.
After observing the lifetime of each tire, the car company reported that the average lifetime of a Good Treads tire is 55,000 miles and the average lifetime of a Speed Tracks tire is 65,000 miles.
Given the car company's report, what conclusion can be made regarding the average lifetime of Good Treads and Speed Tracks tires?
There is not enough information to make any conclusions from the car company's report.
Good Treads' claim is false; therefore, it can be concluded that Speed Tracks tires last longer than Good Treads tires.
Good Treads' claim is false; therefore, it can be concluded that Good Treads tires last longer than Speed Tracks tires.
Good Treads' claim is true; therefore, it can be concluded that Good Treads tires last longer than Speed Tracks tires.
Answers
Good Treads' claim is false; therefore, it can be concluded that Speed Tracks tires last longer than Good Treads tires.
D
The car company's report provides evidence that Speed Tracks tires have a longer average lifetime compared to Good Treads tires. Therefore, we can conclude that Good Treads' claim that their tires last longer is false.
Based on the car company's report, we can conclude that Good Treads' claim that their tires last longer than Speed Tracks' tires is false. The average lifetime of a Good Treads tire is reported to be 55,000 miles, while the average lifetime of a Speed Tracks tire is reported to be 65,000 miles.
To reach this conclusion, we compare the average lifetimes of the two tire brands. Since the car company tested 20 sets of each brand's tires and measured the tread on each tire after simulating 1,000 miles of driving conditions, we can assume that these results are representative.
By comparing the average lifetimes, we see that the average lifetime of Speed Tracks tires is greater than the average lifetime of Good Treads tires. Therefore, we can conclude that Speed Tracks tires last longer than Good Treads tires, contradicting Good Treads' claim.
In conclusion, the car company's report provides evidence that Speed Tracks tires have a longer average lifetime compared to Good Treads tires. Therefore, we can conclude that Good Treads' claim that their tires last longer is false.
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The scale factor of the dilation of figure ABCD is?
Answers
2 is the scale factor of the dilation of figure ABCD
What are coordinates?A pair of numbers called coordinates are used to locate a point or a form in a two-dimensional plane. The x-coordinate and the y-coordinate are two numbers that define a point's location on a 2D plane.
The scale factor of a dilation is a number that represents how much a figure's size alters following a dilation. It is the ratio of similar sides' lengths in the original and dilated figures.
A figure is stretched or extended if the scale factor is larger than 1, and lowered or shrunk if it is less than 1. If the scale factor is 1, the dilation has no effect on the figure; if it is less than 1, the figure is reflected beyond the line of dilation.
The scale factor is represented by the symbol k, and its value may be determined using the formula below:
k = Length of the corresponding side in the dilated figure / Length of the corresponding side in the original figure.
On the given figure,
Before dilation the measurement of the side AD = 1 unit.
After dilation the measurement of the same side = 2 units
Thus, from the formula
k = 2/1
k=2
Therefore, The scale factor of the dilation of Figure ABCD is 2.
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Q #11 Solve the equation
Answers
360*0.67 = 241.2
Your answer is 241°
100% --------> 360 degrees
67% ---------> x
Clearing the value of x we have:
x = (67/100) * (360)
x = 0.67 * 360
x = 241.2 degrees
Rounding off we have:
x = 241 degrees
Answer:
x = 241 degrees
option 4
using a table of value determine the solution to the equation below to the nearest fourth of a unit
2^(-x) + 1 = 5^x + 2
x= -1.50
x= 2.50
x= -0.50
x= 0.75
Answers
f(x) = (2^-x +1) - (5^x +2)
Now, we want to find x so that f(x) = 0.
For the offered choices, we get
f(-1.50) ≈ 1.74
f(-0.50) ≈ -0.03
f(0.75) ≈ -3.75
f(2.50) ≈ -56.72
The obvious choice is
x = -0.50
PLEASE HELP!!!!!! WHICH OF THE FOLLOWING IS A CORRECT EQUATION FOR THE LINE PASSING THROUGH THE POINT (-2 1) AND HAVING SLOPE M = 1/2
Answers
[tex]1= \frac{1}{2} (-2)+2[/tex]
[tex]1= -1+2[/tex]
[tex]1= 1[/tex]
It works, so answer choice A works.
Answer choice B is in slope-intercept (y = mx+b) form. The slope of the line is the number in front of the x, so in this case it's -2. Answer choice B has the wrong slope, so eliminate B.
Answer choice C is in standard form. Rearrange it to slope-intercept form:
[tex]x-2y=-4[/tex]
[tex]-2y=-x-4[/tex]
[tex]y= \frac{1}{2} x+2[/tex]
Same as A, so answer choice C works.
Answer choice D is in point-slope form: y - y1 = m(x - x1). If you know this form well, you should be able to see that the given equation satisfies both the slope and point requirement. If you don't know the form well, try putting it into slope-intercept:
[tex]y-1= \frac{1}{2} (x+2) [/tex]
[tex]y-1= \frac{1}{2} x+1 [/tex]
[tex]y= \frac{1}{2} x+2 [/tex]
Same as A, so answer choice D works.
Indicate the general rule for this sequence. Find a 1 and the common difference. a 4 = 18 a 7 = 9
Answers
The general rule for the sequence is an = -9 + (n-1)(9). The first term (a1) is -9 and the common difference is 9.
Explanation:Sequence Analysis:
To find the general rule for a sequence, we need to determine the pattern or relationship between the terms. In this case, we are given a4 = 18 and a7 = 9. To find the common difference, we subtract the two terms: 18 - 9 = 9. So, the common difference is 9. To find a1, we can use the formula: an = a1 + (n-1)d, where n is the term number and d is the common difference. Substituting n = 4, a4 = 18, and d = 9, we can solve for a1. 18 = a1 + (4-1)(9), which gives us a1 = 18 - 3(9) = 18 - 27 = -9. Therefore, the general rule for this sequence is an = -9 + (n-1)(9). The first term (a1) is -9 and the common difference is 9.
a^1 = 27
d = -3
Step-by-step explanation:
What's a parabola? What's a hyperbola?
Answers
Hyperbola:
In mathematics, a hyperbola (plural hyperbolas or hyperbolae) is a type of smooth curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set. A hyperbola has two pieces, called connected components or branches, that are mirror images of each other and resemble two infinite bows
Hope this Helps
3x^2-2x+7 divided by x+1 what is the quotient?
Answers
Using Syntetic Division:
! 3 -2 7
Divisor: d(x)=x+1→-1 ! -3 5
----------------------
3 -5 12
Quotient: Q(x) = 3x -5
Answer: The quotient is 3x-5
3x^2-2x+7 / x+1
By long division;
x+1 |3x^2-2x+7 = 3x-5
Hope this helps! Goodluck!
One state leads the country in tart cherry production, producing 80 out of every 100 tart cherries each year. a. What percent of tart cherries are produced in this state?
Answers
80/100 = 0.80
80% of tart cherries are produced in this state.
A cat and a dog have a race. The cat’s strides are 30% shorter than the dog’s but it makes 30% more strides than the dog. Which of them will win the race?
Answers
https://brainly.com/question/9994969
Which table represents a linear function? (Will give brainliest)
Answers
Because it is arithmetic.
Answer:
x y
1 0.5
2 1
3 1.5
4 2
Table (1) represents a linear functions.
Step-by-step explanation:
Given : Tables with x and y values.
We have to choose the table that represents a linear function.
Since, A linear function is of the form y = mx + c , where m is slope and c is y- intercept
Consider the table (1),
x y
1 0.5
2 1
3 1.5
4 2
Consider two points , (1,0.5) and (2,1)
0.5 = m(1) + c
and 1 = m(2) + c
Subtract both , we have,
m = 0.5
and Put m = 0.5 back, we have,
c = 0
Thus, y = 0.5x
Thus, Table (1) represents a linear functions.
(a) [5 points] using only the definition, find the laplace transform y (s) of y(t) = e a t where a is a constant. for what values of s does the laplace transform y (s) exist? (b) [10 points] solve, using laplace transforms, the initial value problem: y 00 − 4y 0 + 4y = 3, y(0) = 0, y0 (0) = 1.
Answers
what is the diameter of a circle with a circumference of 30 pi inches
Answers
30π = πD
D = 30 inches
Answer: 30 inches
A basketball is thrown with an initial upward velocity of 30 feet per second from a height of 6 feet above the ground. The equation h=-16t^(2)+30t+6 models the height in feet t seconds after the basketball is thrown. After the ball passes its maximum height, it comes down and then goes into the hoop at a height of 10 feet above the ground. About how long after it was thrown does it go into the hoop?
Answers
h = -16t ^ (2) + 30t + 6
We substitute the value of h = 10 in the equation:
10 = -16t ^ (2) + 30t + 6
Rewriting we have:
0 = -16t ^ (2) + 30t + 6-10
0 = - 16t ^ (2) + 30t - 4
We look for the roots of the polynomial:
t1 = 0.144463904
t2 = 1.730536096
"the ball passes its maximum height, it comes down and then goes into the hoop". Therefore, the correct root is:
t = 1.730536096
Answer:
It goes into the hoop after:
t = 1.73 seconds
An equilateral triangle's perimeter and a rectangle's perimeter have the same numerical value. The length of the rectangle is the same as the side of the triangle. The width of the rectangle is 12. What is the length of the rectangle?
Answers
at the end of his shift, Bruno had $340 worth of tips all in $10 and $20 bills .if he had two more $20 bills than $10 bill .how many of each bill did Bruno have
Answers
David’s starting pay for his summer job is $10.00 per hour. Halfway through the summer he receives a 50 cent per hour raise. David is hired the next summer and receives a 10% raise. Halfway through the second summer he receives a 50 cent per hour raise. David is hired for a third summer and is given a 5% raise. How much money does David earn per hour during the third summer? Show or explain your work.
Answers
The final answer is $12.65
Which type of study contains a treatment?
Sample.
Experiment.
Survey.
Observational study.
Answers
So the answer is experiment.
An experimental set up usually involved random assignment of variables into different group and manipulation of a particular variable while others are controlled. This type of study is usually done to determine the effect of one variable on the outcome of another variable. The experimental set up is usually made up of control and treatment groups.
Conrad and jill have a taxable income of 63,670. they discovered that they are able to receive $1,500 tax credit for purchasing an energy efficient furnace. How will this tax credit affect their taxes?
A) the tax credit will increase their taxable income by $1,500
B) the tax credit will reduce their taxable income by $1,500
C) the tax credit is added to the tax owed, not the taxable income
D) the tax credit is subtracted from the tax owed, not taxable income
Answers
Danny bought 5 candies. Lucy bought 2 fewer than danny. Jimmy bought 4 more than lucy. how many candies did jimmy buy
Answers
Choose any numbers for he first column that will correctly complete the table.
Answers
2. Any number between 9,425 - 9,429
Number: 9,440
In order to accumulate enough money for a down payment on a house, a couple deposits $300/month into an account paying 6% compounded monthly. If payments are made at the end of each period, how much money will be in the account in 5 years? What formula is required to complete this problem?
Answers
[tex]\bf \begin{cases} A= \begin{array}{llll} \textit{accumulated amount}\\ \end{array}\\ pymnt=\textit{periodic payments}\to &300\\ r=rate\to 6\%\to \frac{6}{100}\to &0.06\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{monthly, thus twelve} \end{array}\to &12\\ t=years\to &5 \end{cases}[/tex]
[tex]\bf A=300\left[ \cfrac{\left( 1+\frac{0.06}{12} \right)^{12\cdot 5}-1}{\frac{0.06}{12}} \right]\implies A=300\left[ \cfrac{(1.005)^{60}-1}{0.005} \right] \\\\\\ A=300(\stackrel{\approx}{69.770030509863214)}\implies A\approx 20931.009152958964[/tex]
Use the distributive property to factor the expression below.
54x2y - 12x2y2
Answers
[tex]54 x^{2} y-12 x^{2} y^{2} [/tex]
The term 6x²y can be factored out from both the terms, leaving behind the expression given below.
[tex]6 x^{2} y(9-2y)[/tex]
So,
[tex]54 x^{2} y-12 x^{2} y^{2} = 6 x^{2} y(9-2y)[/tex]
To finance her community college education, Sarah takes out a loan for $3700. After a year Sarah decides to pay off the interest, which is 5% of $3700. How much will she pay?
Answers
3700 + 0.05(3700)
But, if we want to make it shorter:
1.05(3700)
Now you just multiply(you may want to use a calculator)
1.05(3700) = 3885
She will pay $3885
Find the measure of the central angle that you would draw to represent 67% in a circle graft round your answer to the nearest degree
Answers
360 degrees ----> 100%
x -----------------> 67%
Clearing x we have:
x = (67/100) * (360)
x = 241.2 degrees:
round to the nearest degree
x = 241 degrees
Answer:
the measure of the central angle that you would draw to represent 67% in a circle graft is:
x = 241 degrees
then, 67% of 360 degrees is equal to 241.2 degrees
Suppose that $2000 is invested at a rate of 2.1% compounded annually. Assuming that no withdrawals are made find the total amount after 5 years. Do not round any intermediate computations, and round your answer to nearest cent.
Answers
Amount=2,000×(1+0.021)^(5)=2,219
Given the equation f(x) = (x + 3)2 – 8, fill in the blanks:
Axis of symmetry: x =
Vertex:( , )
Number of real solutions:
Answers
In your equation, h = -3 and k = -8.
Axis of symmetry: x = -3
Vertex: (-3, -8)
Number of real solutions: 2
Final answer:
This detailed answer explains the axis of symmetry, vertex, and number of real solutions for the given quadratic equation.
Explanation:
Given the equation f(x) = (x + 3)² – 8
Axis of symmetry: x = -3
Vertex: (-3, -8)
Number of real solutions: 1
Nancy wove a pot holder with a area of 80 square inches. The lengths and widths of the sides are whole numbers. Which dimensions make the most sense for a potholder? Explain
Answers
Since pot holders are normally close to squares, 8 by 10 makes the most sense
Final answer:
The dimensions of 8 inches by 10 inches make the most sense for a pot holder with an area of 80 square inches, as they are practical in size. This is similar to the concept of a square whose area scales by the square of the side length when dimensions are increased by a scale factor.
Explanation:
The student asked which dimensions make the most sense for a potholder with an area of 80 square inches where the lengths and widths are whole numbers. It's crucial to consider practical sizes that would be convenient for handling hot items without being too large or too small.
Common dimensions for a pot holder could be 8 inches by 10 inches since 8 x 10 equals 80 square inches, and these measurements are suitable for a pot holder. These measurements make sense as they provide enough space to protect hands from heat but are not excessively large, making them impractical. They are comparable to the measurements of a placemat, which is typically used in dining settings and is also manageable in size.
Comparing this to the information about squares and areas, if Marta has a square with side length 4 inches, its area would be 16 square inches. A similar square with side lengths that are twice as long (8 inches) would have an area of 64 square inches because the area is proportional to the square of the side length. Consequently, the area of the larger square is four times that of the smaller square (since 2 squared is 4).
This example of scaling dimensions and areas can assist in understanding how dimensions that are whole numbers relate to the area and the practical use of an object. The mentioned scale factor is integral in determining how the area increases with increased side lengths.
cylinder A has a volume of 360 cm3. Cylinder B has a base and height identical to that of cylinder B, but leans to the right in such a way that its slant is greater than 4 cm. what is the volume of cylinder B
Answers
360 cm³.
_____
If the "height" is measured along the central axis of the cylinder, there is insufficient information to determine the volume.
The slant length of a prism (even a cylindrical one) is immaterial. What matters to the volume is the area of the base and the distance between the planes of the bases (height).
360
is the answer
a $1600 principal earns 7% annual interest, compounded semiannually. What is the balance after 33 years?
Answers
FV = P(1 +r/n)^(nt)
FV = 1600*(1 +.07/2)^(2*33)
FV = 1600*1.035^66 ≈ 15,494.70
The balance after 33 years will be $15,494.70