Question

Given f(x)=2x^3-7 find f^-1(x) and then find f^-1(-2)

I though that this meant inverse function.

x=2y^3-7
x+7=2y^3
(x+7)/2=y^3
((x+7)/2)^(1/3)=y

so this meant f^-1(-2) = 1.35721

The professor posted the answer as being 6. I'm not sure if I misunderstood the question or if I'm completely off in my answer.

Any ideas?

thanks

Answer 1

It looks correct to me