Question

-4 -6 cos x = -4 -4 cos x for 0degrees less then or equal to x less then or equal to 180 degrees

Answer 1

x = 90°

Explanation:

Given

- 4 - 6cosx = - 4 - 4cosx ( add 4cosx to both sides )

- 4 - 2cosx = - 4 ( add 4 to both sides )

- 2cosx = 0, hence

cosx = 0

x =
`cos^(-1)`(0) = 90° for 0 ≤ x ≤ 180