Question

cosx/1 + sinx + cosx/1-sinx

помогите, не шарю

Answer 1

Cosx/1 + sinx + cosx/1-sinx = cos x(1-sinx) + cosx(1+sinx) /(1+sinx)(1-sinx)=
=cosx - cosx*sinx + cosx + cosx*sinx / (1- sin^2x) = 2 cos x/ cos^2 x = 
= 2/cos x