Answer:
A.
Step-by-step explanation:
π/4 radians = 45°
In a 45-45-90 degree angle, the ratio of the lengths of the sides is
1 : 1 : √2
x = y = 1/√2
x = y = √2/2
Answer: A.
A
π/4 rad is 45°
cos 45° and sin 45° are both equal to (√2 / 2)
If you're curious, cos delta = x-coordinate while sin delta = y-coordinate
