Question

sin a + tg a/1+cos a помогите упростить выражение

Answer 1

sin a (sin a/(1-cos a) - 1/tg a) = =sin a (sin a*tga- (1-cos a))/tg a = =cos a *(sin a*tga- 1+cos a)= =sin^2 a - cos a+cos^2 a=1-cos a=2sin ^2 (a2)