Question

helpp

Answer 1

solve it like a quadratic
\[2x^2 -3x +1 = 0\]
\[(2x-1)(x-1) = 0\]
\[x = \frac{1}{2}, 1\]
\[\cos \theta = \frac{1}{2} , 1\]

Answer 2

let cos deta be x