Question

помогите срочно!!!!!

Answer 1

Пошаговое объяснение:

$2 \cos ^{2} ( x ) + 5 \sin(x) - 4 = 0 \\ 2(1 - \sin^{2} (x)) + 5 \sin(x) - 4 = 0 \\ - 2 - 2 \sin^{2} (x) + 5 \sin(x) = 0 \\ t = \sin(x) \\ - 2 - 2 {t}^{2} + 5t = 0 \\ d = 25 - 4 \times - 2 \times - 2 = 9 \\ t1 = \frac{ - 5 + 3}{ - 4} =0.5 \\ t2 = \frac{ - 5 - 3}{ - 4} = 2 \\ \sin(x) = 0.5 \\ \sin(x) = 2 \\ x = \frac{\pi}{6} + 2k\pi \\ k(z) \\ x = \frac{5\pi}{6} + 2k\pi \\ k(z)$

k(z) - это знак принадлежности.