Question

Помогите решить
$\cos ^{2} (x) + \sin(x) = \sqrt{2} \times \sin(x \ + \pi \div 4)$

Answer 1

$\cos^2x+\sin x=\sqrt{2}\times \sin(x+\frac{\pi}{4})\\ \cos^2x+\sin x=\sqrt{2}\times (\sin x\cos\frac{\pi}{4}+\cos x\sin\frac{\pi}{4})\\ \cos^2x+\sin x=\sqrt{2}\times(\frac{1}{\sqrt{2}}\sin x+\frac{1}{\sqrt{2}}\cos x)\\ \cos^2x+\sin x=\sin x+\cos x\\ \cos^2x-\cos x=0\\ \cos x(\cos x-1)=0\\ x_1=\frac{\pi}{2}+\pi n,n \in Z\\ x_2=2\pi n,n \in Z$