Answer:
ummm im not good at math
Step-by-step explanation:
but i need points
Answer:4 2/3
cosx = sqrt(15)/4, -sqrt(15)/4
cos²x = 1 - sin²sin x
cos²x = 1 - (1/4)²
cos²x = 15/16
Here is your answer
HOPE IT IS USEFUL
I think it's (A). if not it's (C)