DearMHFmembers,

I met somewhere an integral inequality as follows.

$\displaystyle \int_{\tau(a)}^{\tau(b)}f(x)\int_{x}^{b}g(y) \mathrm{d}y \mathrm{d}x\geq\int_{a}^{b}g(y)\int_{\tau(a)}^{ \tau(y)}f(x) \mathrm{d}x \mathrm{d}y,$

where $\displaystyle f,g$ are nonnegative continuous functions

and $\displaystyle \tau$ is a nondecreasing function with $\displaystyle \tau(x)\leq x$.

Have any of you met before with something like this

or can help me how to deduce this?

Thank you very much.

bkarpuz