# Inequality with 4 variables

1. Apr 21, 2012

### a4b3c2d1e0f

Good day, I have this problem that appeared in some practical problem that I'm working on.
I basically want to find the boundaries of a,b,c,d for which the following inequality is satisfied, if a,b,c,d $\in$ ℝ$^+$ and the inequality is:
$-2 \cdot d + c - a \cdot (c \cdot d)^2 + a \cdot c + \frac{1}{a \cdot c \cdot b^2} \ge 0$
How would one approach such a problem, to find the exact solution set?
I'm not really expecting you to solve it, but I'd very much like to hear some advice on how to approach such a problem, to get some information from it, because I want to learn something new.
Thanks

Last edited: Apr 21, 2012