Question

3+2(cos^2x-1)=cosx+1 find the positive values of x less than 2pi that satisfy the equation

Answer 1

youve got a quadratic ... using the quadratic formula would be a good idea.

Answer 2

let cos(x) = t

3 + 2(t^2-1) = t + 1

solve for the unknown, regardless of what we call it.