Question

ПОМОГИТЕ, ПОЖАЛУЙСТА)
$frac{2 cos^{2} 68^{0}-1}{2cos 113^{0}*sin 67^{0}}$
$frac{6 cos^{2} 34^{0}-3}{cos 169^{0}*cos79^{0}}$

Answer 1

(2сos²(68)-1)/(2cos(113)*sin(67))=сos136/2cos(180-67)sin67=
=cos136/(-2cos67sin67)=-cos136/sin134=-cos(90+46)/sin(180-46)=sin46/sin46=1