Question

Найдите sin,tg,ctg,если cos b=3/4 2п

Answer 1

sinb=-√(1-cos²b)=-√(1-9/16)=-√(7/16)=-√7/4
tgb=sinb/cosb=-√7/4:3/4=-√7/4*4/3=-√7/3
ctgb=1/tgb=-3/√7