First, factor the quadratic equation:
\(8 \cos^2 \theta - 10 \cos \theta + 2 = 0\)
can be factored as \(2(4 \cos \theta - 1)(\cos \theta - 1) = 0\).
This gives two equations:
1. \(4 \cos \theta - 1 = 0\)
2. \(\cos \theta - 1 = 0\)
Solving the first equation:
\(4 \cos \theta = 1\)
\(\cos \theta = \frac{1}{4}\)
\(\theta = 75.5^\circ\) (using a calculator for inverse cosine)
Solving the second equation:
\(\cos \theta = 1\)
\(\theta = 0^\circ\)
Thus, the solutions are \(\theta = 0^\circ\) and \(\theta = 75.5^\circ\).