Question

A prepaid cellular phone charges $25 for activation and $0.05 per minute. The relation of cost to minutes canbe defined by the function (x) - 0.05x + 25 What is the inverse of the function? #6 -- 20x500c. F'(x) = -0.05x-25d. F'(x) - 20x - 5001A from the questionB from the questionC from the questionD from the questionBack

Answer 1

the function is

$c(x)=0.05x+25$

we can change c(x) to x and x to c-1(x)

$x=0.05c^{-1}(x)+25$

now, solve c-1(x)

$\begin{gathered} x-25=0.05c^{-1}(x) \\ c^{-1}(x)=\frac{x-25}{0.05} \\ c^{-1}(x)=20x-500 \end{gathered}$

so, the answer is D