Нужна помощь. Тригонометрия.

Решите задачу:

$-1 \leq sin \alpha \leq 1 \\\ 0 \leq sin^2 \alpha \leq 1 \\\ 0 \leq 4sin^2 \alpha \leq 4 \\\ -1 \leq cos \alpha \leq 1 \\\ 0 \leq cos^2 \alpha \leq 1 \\\ -1 \leq -cos^2 \alpha \leq 0 \\\ -1 \leq 4sin^2 \alpha -cos^2 \alpha \leq 4$

$-1 \leq sin \alpha \leq 1 \\\ 0 \leq sin^4 \alpha \leq 1 \\\ 0 \leq 3sin^4 \alpha \leq 3 \\\ -1 \leq cos \alpha \leq 1 \\\ 0 \leq cos^4 \alpha \leq 1 \\\ -1 \leq -cos^4 \alpha \leq 0 \\\ -1 \leq 3sin^4 \alpha -cos^4 \alpha \leq 3$