Question

cos (3x+π/4)=корень2/2

Answer 1

$cos(3x + frac{pi}{4} ) = frac{ sqrt{2} }{2} \ 3x + frac{pi}{4} = frac{pi}{4} + 2pi n \ 3x = 2pi n \ x = frac{2pi}{3} n, : n in Z$