Question

Given the function f(x) = 3x, find the value of f−1(27).

Answer 1

the value of f-1(27) is 9.

In order to find this answer, we first have to find the inverse function (since that is what f-1 means). To do this, we switch the f(x) value and the x. Then we solve for the new f(x). The result is the inverse function. The work for this is below.

f(x) = 3x ----> Switch the f(x) and the x.

x = 3f(x) ---> divide by 3.

f-1(x) = $\frac{x}{3}$.

Now that we have this, we can plug in 27 (the number in parenthesis) and find the result.

f-1(x) = $\frac{x}{3}$

f-1(27) = $\frac{27}{3}$

f-1(27) = 9