How do you find the inverse of #g(x)=x^3-1#?

1 Answer
Dec 1, 2015

#g^(-1)(x) = root(3)(x+1)#

Explanation:

To find the inverse of a function, we can let #y = f(x)# and then solve for #x# to obtain #x = f^(-1)(y)#.
(Note that it should make sense as to why that is the inverse function obtained, as applying it to the original function #y=f(x)# returns #x#)

Applying this here:

Let #y = g(x) = x^3 - 1#

#=> y+1 = x^3#

#=> root(3)(y+1) = x#

Thus we get #g^(-1)(y) = root(3)(y+1)# meaning

#g^(-1)(x) = root(3)(x+1)#