Question

Cos() =

O A. 2
2
○ B.
Oc.
O D.
12
ㅊ
뭐~
욜
2

Answer 1

A

Explanation:

cos (90°+α) = sin α

or cos (π/2 + α) = sin α

Now, 3π/4 = π/2 + π/4

cos (3π/4) = cos (π/2 + π/4) = sin (π/4)

sin (π/4) = √2/2