2cos(90-α)*sin(90+α)*tg(180-a) ________________________ Cotg(90-a)*sin(180-a) α=30

Question

2cos(90-α)*sin(90+α)*tg(180-a)
________________________
Cotg(90-a)*sin(180-a)

α=30

Answer 1

-2·sina·cosa·tga   | tga·sina =  -2cosa=-2cos30°=-2·√3/2=-√3