# Math Help - help me to find the inverse function

1. ## help me to find the inverse function

find the inverse of the function f(x)=x^2 - 3x

2. Originally Posted by nmaths
find the inverse of the function f(x)=x^2 - 3x
The function does not posess an inverse.
Because it is not one-to-one. For example, $f(3)=f(0)$ and $3\not = 0$.
Perhaps you mean on a restricted domain?

3. Well, you can find an inverse for (say) x>0. The way to find inverses is rather limited: equate y=f(x) and solve for x. That is the inverse function x=g(y).

Here, we have y=f(x)=x^2-3x or x^2-3x-y=0. Solve this (quadratic for x), and you have obtained the inverse function.