Question

Solve this pleaseplease​

Answer 1

Answer:

Step-by-step explanation:

cos(2a) = cos^2(a) - sin^2(a)

cos(2a) = 2cos^(a) - 1

cos(2a) = 11/25

11/25 = 2 cos^(a) - 1             Add 1 to both sides

1 + 11/25 = 2 cos^2

25/25 + 11/25 = 2 cos^2(a)

36/25 = 2 cos^2 (a)            Divide by 2

36/50 = cos^2 (a)               Take the square root of both sides.

6/5*sqrt(2) = cos(a)