Question

Решите уравнение :
sinx/cos²x/2=4sin²x/2

Answer 1

$\frac{sinx}{cos^2\frac{x}{2}}=4sin^2\frac{x}{2}\; \to \; \; cos^2\frac{x}{2}\ne 0\; ,\; \frac{x}{2}\ne \frac{\pi }{2}+\pi n,\; x\ne \pi +2\pi n,\; n\in Z\\\\\frac{sinx}{4sin^2 \frac{x}{2}\cdot cos^2\frac{x}{2}}=1\\\\\frac{sinx}{(2sin\frac{x}{2}\cdot cos\frac{x}{2})^2}=1\\\\ \frac{sinx}{sin^2x}=1\\\\\frac{1}{sinx}=1\\\\sinx=1\\\\\underline {x=\frac{\pi}{2}+2\pi n\; ,\; n\in Z}$