Question

Тригонометрия срочно !!!!!!!

Answer 1

$displaystyle frac{6cos^234а-3}{cos169аcos79а} = frac{3(2cos^234а-1)}{cos(180а-11а)cos(90а-11а)} = frac{3cos68а}{-cos11аsin11а} =\ \ \ =- frac{6cos(90а-22а)}{2sin11аcos11а} =- frac{6sin22а}{sin22а} =-6$