Math assingment

Question

Find all solutions to the equation . Write your answer in radians in terms of 

Answer 1

-4 Cos(x) = -Sin²(x) + 1

= -(1-Cos²(x)) + 1

= Cos²(x)

Cos²(x) + 4Cos(x) = 0

Cos(x) [ Cos(x) + 4] = 0

x = nπ/2 for n=1 to ∞