Given the following functions, find the indicated values f(x) = 8 - 4x (a) f(-8) (b) f(c) (c) f(9) (a) f(-8)=blank

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

Sketch one cycle if the cosine function y=2cos2theta

Precalculus question, image attached.