Question Number 27706 by shivamgiri last updated on 13/Jan/18
$${the}\:{number}\:{of}\:{x}\epsilon\left[\mathrm{0},\mathrm{2}\pi\right]{for}\:{which}\mid\sqrt{}\mathrm{2}{sin}^{\mathrm{4}\:} {x}+\mathrm{18}{cos}^{\mathrm{2}} {x}−\sqrt{\mathrm{2}{cos}^{\mathrm{4}} {x}+\mathrm{18}{sin}^{\mathrm{2}} {x}}\mid=\mathrm{1} \\ $$