Сколько будет 3cos((7п/2) - x)???

Question

Сколько будет 3cos((7п/2) - x)???

Answer 1

Решение
3cos((7п/2) - x) = 3*cos([6π/2 + (π/2 - x)] = 3*cos[3π + (π/2 - x)] =
= - 3*cos(π/2 - x)] = - 3sinx