Question

Question #98a5e

Answer 1

`x={pi/4,(7*pi)/4}`

Explanation:

First subtract 16 from both sides and then divide both sides by 2 to get: `cos^2(x)=1/2`. Then square root both sides to get `cos(x)=1/(sqrt(2))`. Cosine only equals this at angles `pi/4` and `(7*pi)/4` (within a range from 0 to `2*pi`) so those two angles are our answers. Hope I helped!