# Simple question in Mathematica: find value of function

• Mathematica

## Main Question or Discussion Point

Hi guys!

I'm trying to the value of x when a function F[x] has a certain expression. I'm computing the value of F[x] using NDSolve and a set of differential equations - all numerically. Yet, I cant find an easy and systematic way to find the value of x when F[x]=constant.

I tried using NMinimize:
Code:
NMinimize[{Evaluate[CONSTANT-
F[x] /. systemofequations, x]
Yet, I cant seem to find a good way to compute the value of x.. :S

Do you guys have any suggestions on how I could try to solve this issue?
Thanks so much