Question Number 173393 by Shrinava last updated on 10/Jul/22
$$\mathrm{If}\:\:\mathrm{a},\mathrm{b}\geqslant\mathrm{0}\:\:\mathrm{then}\:\mathrm{prove}\:\mathrm{that}: \\ $$$$\int_{\boldsymbol{\mathrm{a}}} ^{\:\boldsymbol{\mathrm{b}}} \int_{\boldsymbol{\mathrm{a}}} ^{\:\boldsymbol{\mathrm{b}}} \:\mid\mathrm{ay}−\mathrm{ab}\:+\:\mathrm{bx}\mid\:\mathrm{dydx}\:\leqslant\:\mathrm{a}^{\mathrm{2}} \mathrm{b}^{\mathrm{2}} \\ $$