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2 years ago

Which of the following could be used to calculate the area of a sector in the circle shown below

Mathematics

1 answer:

lara [203]2 years ago

8 0

Answer:

Therefore the Last option is correct

$\textrm{Area of Sector ACD}=\pi (8\ in)^{2}\times (\frac{42}{360})$

Step-by-step explanation:

Given:

Radius = r = 8 in

θ = 42°

To Find:

Area of Sector = ?

Solution:

We know that

$\textrm{Area of Sector}=\pi (Radius)^{2}\times \frac{\theta}{360}$

Substituting the given values in the formula we get

$\textrm{Area of Sector ACD}=\pi (8\ in)^{2}\times (\frac{42}{360})$

Which is the required Answer.

Therefore the Last option is correct

$\textrm{Area of Sector ACD}=\pi (8\ in)^{2}\times (\frac{42}{360})$

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Write the equation for the following relation. R = {(x, y): (4, 5), (8, 7), (12, 9), (16, 11), . . .} and show work

timama [110]

Let

A(4,5) B(8,7) C(12,9) D(16,11)

1) Find the slope AB

m=(y2-y1)/(x2-x1)

m=(7-5)/(8-4)=0.5

2) Find the slope BC

m=(9-7)/(12-8)=0.5

3) Find the slope CD

m=(11-9)/(16-12)=0.5

The points represent a linear function

<u>Find the equation of the line with m=0.5 and the point A(4,5)</u>

we know that

y-y1=m*(x-x1)

y-5=0.5*(x-4)

y=0.5*x-2+5

y=0.5*x+3

therefore

<u>the answer is</u>

The equation is equal to y=0.5*x+3

8 0

2 years ago

Can somebody please help me. I would really appreciate it

laila [671]

90=6x+3x
90=9x
90/9=x
10=x

3x=3*10=30
6x=6*10=60
hope this helped

4 0

2 years ago

2|3x + 5| = -10 how break it down

iren2701 [21]

2|3x + 5| = -10 . Divide both sides by 2:

|3x + 5| = -5 ===>3x+5=-5 & -3x-5=-5 In both cases x=0

6 0

2 years ago

Find the area of the triangle formed by the origin and the points of intersection of parabolas y=− 1/3 (x−1)^2+8 and y=x^2−2x−3.

Kobotan [32]

Answer:

The area of the triangle formed by origin, and the points (4,5) and (-2,5) will be 15 sq. units.

Step-by-step explanation:

The two parabolas are $y = - \frac{1}{3}(x - 1)^{2} + 8$ and y = x² - 2x - 3.

Now, solving those two equations we will get the points of intersection.

So, $- \frac{1}{3}(x - 1)^{2} + 8 = x^{2} - 2x - 3$

⇒ - (x - 1)² + 24 = 3x² - 6x - 9

⇒ -x² + 2x - 1 + 24 = 3x² - 6x - 9

⇒ 4x² - 8x - 32 = 0

⇒ x² - 2x - 8 = 0

⇒ x² - 4x + 2x - 8 = 0

⇒ (x - 4)(x + 2) = 0

So, x = 4 or - 2.

Now, for x = 4 , y = 4² - 2(4) - 3 = 5 and the point of intersection is (4,5).

Or, for x = - 2, y = (- 2)² - 2(- 2) - 3 = 5 and the point of intersection is (-2,5).

Now, points (4,5) and (-2,5) make a straight line parallel to the x-axis at a perpendicular distance of 5 units from origin and its length is (4 - (- 2)) = 6 units.

So, the area of the triangle formed by origin, and the points (4,5) and (-2,5) will be = 0.5 × 5 × 6 = 15 sq. units. (Answer)

8 0

2 years ago

An experiment to investigate the survival time in hours of an electronic component consists of placing the parts in a test cell

mixer [17]

Answer:

a) The sample mean is of 49 and the sample standard deviation is of 11.7.

b) The range of the true mean at 90% confidence level is of 9.62 hours.

c) The prediction interval, at a 90% confidence level, of it's failure time is between 39.38 hours and 58.62 hours.

Step-by-step explanation:

Question a:

Sample mean:

$\overline{x} = \frac{34+40+46+49+61+64}{6} = 49$

Sample standard deviation:

$s = sqrt{\frac{(34-49)^2+(40-49)^2+(46-49)^2+(49-49)^2+(61-49)^2+(64-49)^2}{5}} = 11.7$

The sample mean is of 49 and the sample standard deviation is of 11.7.

b)Determine the range of the true mean at 90% confidence level.

We have to find the margin of error of the confidence interval. Since we have the standard deviation for the sample, the t-distribution is used.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 6 - 1 = 5

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 5 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.9}{2} = 0.95$ . So we have T = 2.0.150

The margin of error is:

$M = T\frac{s}{\sqrt{n}}$

In which s is the standard deviation of the sample and n is the size of the sample. So

$M = 2.0150\frac{11.7}{\sqrt{6}} = 9.62$

The range of the true mean at 90% confidence level is of 9.62 hours.

(c)If a seventh sample is tested, what is the prediction interval (90% confidence level) of its failure time.

This is the confidence interval, so:

The lower end of the interval is the sample mean subtracted by M. So it is 49 - 9.62 = 39.38 hours.

The upper end of the interval is the sample mean added to M. So it is 49 + 9.62 = 58.62 hours.

The prediction interval, at a 90% confidence level, of it's failure time is between 39.38 hours and 58.62 hours.

4 0

2 years ago