Question

(корень из 2)cosx-1=0
pls help fast

Answer 1

$\sqrt{2}Cosx-1=0\\\\\sqrt{2}Cosx=1\\\\Cosx=\frac{1}{\sqrt{2}} \\\\x=\pm arcCos\frac{1}{\sqrt{2}}+2\pi n,\in Z \\\\\boxed{x=\pm\frac{\pi }{4}+2\pi n,n\in Z}$