Question

if I have f(x)=x^3-ax+8 and they give f^-1(23)=3 how do i solve for a?

Answer 1

or rather, find out when x=3 and y=23, what does a equal?

Answer 2

23 =(3)^3-3a+8

15 =27 - 3a

5 =9 - a

a = 4

Answer 3

i get the right thought eventually ;)

Answer 4

Omg it seems so simple now lol

Answer 5

yep; just remember that an inverse is a relationship between x and y such that:

f(x) = y ; f-1(y)=x

Answer 6

thank you so much (: