Find the area of the shaded regions. Give your answer as a completely simplified exact value in terms of π (no approximations).
1 answer:
Hello!
The formula for the area of a sector can be written as follows:
Area =
(R)
In the above formula, “r” represents the radius while “R” represents the radian measure of a sector. The radius is given to us in the image above as 10 inches. However, we still need the radian measure of the two sectors. To find this measure, we can use the following conversion:
1 degree =
radians
Because the two sectors have a given measure of 72 degrees, we need to multiply both sides of the above conversion by 72:
72 degrees =
Reduce the fraction on the right side of the equation:
72 degrees =
We now have the radian measure of both sectors. Now simply insert this and any other known values into the “area of a sector” formula above:
Area =
()
Simplify the right side of the equation to get the following answer:
Area = 20 pi
We have now proven that the area of one sector is equal to 20 pi.
If, however, you need the combined area of the two identical sectors, simply multiply the proven area by 2 to get a total area of 40 pi.
I hope this helps!
The formula for the area of a sector can be written as follows:
Area =
In the above formula, “r” represents the radius while “R” represents the radian measure of a sector. The radius is given to us in the image above as 10 inches. However, we still need the radian measure of the two sectors. To find this measure, we can use the following conversion:
1 degree =
Because the two sectors have a given measure of 72 degrees, we need to multiply both sides of the above conversion by 72:
72 degrees =
Reduce the fraction on the right side of the equation:
72 degrees =
We now have the radian measure of both sectors. Now simply insert this and any other known values into the “area of a sector” formula above:
Area =
Simplify the right side of the equation to get the following answer:
Area = 20 pi
We have now proven that the area of one sector is equal to 20 pi.
If, however, you need the combined area of the two identical sectors, simply multiply the proven area by 2 to get a total area of 40 pi.
I hope this helps!
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Answer:
Probability that a battery will last more than 19 hours is 0.0668.
Step-by-step explanation:
We are given that the lifetime of a battery in a certain application is normally distributed with mean μ = 16 hours and standard deviation σ = 2 hours.
<em>Let X = lifetime of a battery in a certain application</em>
So, X ~ N()
The z-score probability distribution for normal distribution is given by;
Z = ~ N(0,1)
where, = mean lifetime = 16 hours
= standard deviation = 2 hours
The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X.
So, the probability that a battery will last more than 19 hours is given by = P(X > 19 hours)
P(X > 19) = P( >
) = P(Z > 1.50) = 1 - P(Z
1.50)
= 1 - 0.9332 = 0.0668
<em>Now, in the z table the P(Z </em><em> x) or P(Z < x) is given. So, the above probability is calculated by looking at the value of x = 1.50 in the z table which has an area of 0.9332.</em>
Hence, the probability that a battery will last more than 19 hours is 0.0668.