Inverse question.....?

Question

I have an equation and i need to find the inverse

.03x^3 - 25.395=Y

I came up with the

cubic-root of(846.5+33.33333333x) = y

Answer 1

y = 0.03x^3 - 25.395.

to find the inverse of this function, we must first express x in terms of y.

x^3 = y/.03 + 25.395/.03

     = 100y/3 + 846.5

x = cube root of (100y/3 + 846.5)

now, we have to interchange y and x:

y = cube root of ( 100x/3 + 846.5 ).

2) f(x) = -(3/500)x^4 + (13/25)x^2 + 11/4.

this function is not one-to-one. therefore it doesn't have an inverse.