Question

Решите пожалуйста
cos(πx/4)=√2/2

Answer 1

$Cos(\frac{\pi x}{4})=\frac{\sqrt{2}}{2}\\\\\frac{\pi x}{4}=\pm arcCos\frac{\sqrt{2} }{2}+2\pi n,n\in Z\\\\\frac{\pi x}{4}=\pm \frac{\pi }{4} +2\pi n,n\in Z\\\\x=\pm1+8n,n\in Z$