Question

Given f(x) = 6x^4, find f^-1(x). Then state whether f^-1 (x) is a function.

A. Y=+or-(x/6)^4; f^-1(x) is not a function
B. Y= +or- (x/6)^4 ; f^-1(x) is a function
C. Y= +or- (x/6)^1/4 ; f^-1(x) is a function
D. Y= +or- (x/6)^1/4 ; f^-1(x) is not a function

Answer 1

D. Y= +or- (x/6)^1/4 ; f^-1(x) is not a function

Explanation:

A function g is the inverse of function f if for y=f(x), x=g(y).

y = 6x^4

Replace x with y:

x = 6y^4

Solve for y:

+or- x^1/4 = 6y

+or- (x/6)^1/4 = y

For each x there are 2 values of y: negative and positive. So, it is not a function.