Question

cos(x−π/2)sinπ/6−cosxcos7π/6=0

Answer 1

sinx*sinπ/6-cosx*cos(π+π/6)=0
sinx*sinπ/6-cosx*(-cosπ/6)=0
sinx*sinπ/6+cosx*cosπ/6=0
cos(x-π/6)=0
x-π/6=π/2+πn
x=2π/3+πn,n∈z

Answer 2

Вы меня спасаете уже не раз. И я благодарен Вам)