Question

Найти значение выражения
Спасайте ребят !)

Answer 1

1) sin(π/2 + α)/cos(π + α) = cosα/ (-cosα) = -1

2) cos (π/2 + α) · ctg (π - α) = -sinα · cos(π - α)/sin (π - α) =

= -sinα · (-cosα)/sinα = cosα

3) sin(π/2 + α) - cos(π - α) + tg(π + α) + ctg(5π/2 - α) =

= cosα - (-cosα) - tgα + tgα = 2cosα

4) cos (α - π/2) = cos(π/2 - α) = sinα