Упростить Cos(3π\2-a)

Question

Упростить
Cos(3π\2-a)

Answer 1

Cos(3П/2 - а) = соs(3П/2)cos(a) + sin(3П/2)sin(a) = 0cos(a) - 1sin(a) = 0 - sin(a) = -sin(a)

Comments

Спасибо