We actually don't need to do any computation. By definition, the inverse function 
changes the role of input and output. So, if a function f maps x onto y, the inverse function maps y onto x.
You have to think like this: if the function makes a step further, the inverse function makes that same step back.
This means that the composition 
is always the identity function 
. In fact,
So, for every function, you have
Answer:
x = tan⁻¹(⅘)
Step-by-step explanation:
We can solve for x by using trigonometric ratios (sin, cos, and tan)
We need to apply the appropriate ratio that uses the two sides 8 and 10 from the perspective of x. See attached image for information about ratios. (Source: Math is Fun)
The tangent ratio is opposite divided by adjacent. It will relate x to the two sides. So we would write
tan(x) = ⁸⁄₁₀
Then we simplify and move the tan to the other side by multiplying both sides by the inverse of tan (since you cannot divide by tan)
tan(x) = ⅘
x = tan⁻¹(⅘)
Then we can use a calculator to evaluate x
If you want to find y, now that you have two angles of the triangle, you can find the sum of 90 + x and subtract that from 180 (since all angles of a triangle add up to 180) to find y.
Answer:
n = 12 nickels
d = 11 dimes
q = 7 quarters
Step-by-step explanation:
.05n + .1d + .25q = 3.45
n + d + q = 30
n = q + 5
n = 12
d = 11
q = 7
Answer:
A
Step-by-step explanation:
Edge 2021
(a) Average time to get to school
Average time (minutes) = Summation of the two means = mean time to walk to bus stop + mean time for the bust to get to school = 8+20 = 28 minutes
(b) Standard deviation of the whole trip to school
Standard deviation for the whole trip = Sqrt (Summation of variances)
Variance = Standard deviation ^2
Therefore,
Standard deviation for the whole trip = Sqrt (2^2+4^2) = Sqrt (20) = 4.47 minutes
(c) Probability that it will take more than 30 minutes to get to school
P(x>30) = 1-P(x=30)
Z(x=30) = (mean-30)/SD = (28-30)/4.47 ≈ -0.45
Now, P(x=30) = P(Z=-0.45) = 0.3264
Therefore,
P(X>30) = 1-P(X=30) = 1-0.3264 = 0.6736 = 67.36%
With actual average time to walk to the bus stop being 10 minutes;
(d) Average time to get to school
Actual average time to get to school = 10+20 = 30 minutes
(e) Standard deviation to get to school
Actual standard deviation = Previous standard deviation = 4.47 minutes. This is due to the fact that there are no changes with individual standard deviations.
(f) Probability that it will take more than 30 minutes to get to school
Z(x=30) = (mean - 30)/Sd = (30-30)/4.47 = 0/4.47 = 0
From Z table, P(x=30) = 0.5
And therefore, P(x>30) = 1- P(X=30) = 1- P(Z=0.0) = 1-0.5 = 0.5 = 50%
