Question

Помогите, пожалуйста tgXcosX=sinX+cos3X

Answer 1

tg(x)*cos(x) = sin(x)+cos(3*x)
tgx cosx=cosx tgx
sinx+cos(3x)=cos(3x)+sinx
cosx tgh=cos(3x)+sinx
sinx=cos(3x)+sinx
2πk/3+π/6;2πk/3-π/6
Ответ:x ∈ {2*π*k/3-π/6, 2*π*k/3+π/6}, k ∈ Z