SOLUTION: how do you find the inverse of a problem such as f(x)= -2x^3+1 or a problem such as g(x)= 1/x-1

Algebra ->  Rational-functions -> SOLUTION: how do you find the inverse of a problem such as f(x)= -2x^3+1 or a problem such as g(x)= 1/x-1      Log On


   

Question 463306: how do you find the inverse of a problem such as f(x)= -2x^3+1
or a problem such as g(x)= 1/x-1
Found 2 solutions by robertb, edjones:
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Solve for x in terms of y:
y+-+1+=+-2x%5E3
<==>%281-y%29%2F2+=+x%5E3
<==>+x+=+root%283%2C+%281-y%29%2F2%29
Interchange the places of x and y:
==> y+=+root%283%2C+%281-x%29%2F2%29. This is the inverse function.

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)= -2x^3+1
y=-2x^3+1
x=-2y^3+1
-2y^3=x-1
y^3=(1-x)/2
y=%28%281-x%29%2F2%29%5E%281%2F3%29
f%5E-1%28x%29=%28%281-x%29%2F2%29%5E%281%2F3%29
.
Ed