Cos7x - √3sin7x = -√2

Question

Cos7x - √3sin7x = -√2

Answer 1

1/2cos7x-sqrt(3)/2sin7x=-sqrt(2)/2
sin(П/6-7x)=-sqrt(2)/2
П/6-7x=(-1)^(k+1)п/4+Пk
7x=П/6-(-1)^(k+1)п/4+Пk
x=П/42+(-1)^lП/28+Пl/7