Пошаговое объяснение:
A) sin(π/2 + t) = √3/2
cos(t) = √3/2
t = +- π/3 + 2πk, k∈Z
Б) 2cos²t + sint + 1 = 0
2 - 2sin²t + sint + 1 = 0
2sin²t - sint - 3 = 0
D = 1 + 24 = 25
sint = (1 + 5)/4 = 3/2 > 1 - не подходит
sint = (1 - 5)/4 = -1
t = -π/2 + 2πk, k∈Z
