104 помогите!!!!!!!!!!!!!!!!!!!

Решите задачу:

$1)\quad tg2 \alpha =1\; ,\; \; \alpha \in [-\pi ,\pi ]\\\\2 \alpha =\frac{\pi}{4}+\pi n,\; n\in Z\\\\ \alpha =\frac{\pi}{8}+\frac{\pi n}{2}\; ,\; n\in Z\\\\ \alpha \in [-\pi ,\pi ]\; :\; \; \alpha =-\frac{7\pi}{8}\; ,\; -\frac{3\pi}{8}\; ,\; \frac{\pi }{8}\; ,\; \frac{5\pi }{8}\\\\2)\quad cos2 \alpha =0\; ,\; \; \alpha \in [-2\pi ,2\pi ]\\\\2 \alpha =\frac{\pi}{2}+\pi n,\; n\in Z\\\\ \alpha =\frac{\pi}{4}+\frac{\pi n}{2},\; n\in Z\\\\ \alpha \in [-2\pi ,2\pi ]:\\\\\alpha =- \frac{7\pi }{4},-\frac{5\pi }{4},\; -\frac{3\pi }{4},\; -\frac{\pi }{4},\; \frac{\pi }{4},\; \frac{3\pi }{4},\; \frac{5\pi }{4},\; \frac{7\pi }{4}\; .$

$3)\quad sin2 \alpha =0\; ,\; \alpha \in [0,2\pi ]\\\\2 \alpha =\pi n,\; n\in Z\\\\ \alpha =\frac{\pi n}{2},\; n\in Z\\\\ \alpha \in [0,2\pi ]:\; \; \alpha =0,\; \frac{\pi}{2},\; \pi ,\; \frac{3\pi }{2},\; 2\pi \; .$

$4)\quad cos2 \alpha =-1\; ,\; \; \alpha \in [-3\pi ,0]\\\\2 \alpha =\pi +2\pi n,\; n\in Z\\\\ \alpha =\frac{\pi}{2}+\pi n,\; n\in Z\\\\ \alpha \in [-3\pi ,0]:\; \; \alpha =-\frac{5\pi}{2},\; -\frac{3\pi}{2},\; -\frac{\pi}{2}\; .$