Question

Тригонометрия срочно !!!!!!!

Answer 1

$\displaystyle \frac{6\cos^234а-3}{\cos169а\cos79а} = \frac{3(2\cos^234а-1)}{\cos(180а-11а)\cos(90а-11а)} = \frac{3\cos68а}{-\cos11а\sin11а} =\\ \\ \\ =- \frac{6\cos(90а-22а)}{2\sin11а\cos11а} =- \frac{6\sin22а}{\sin22а} =-6$