Solve each equation on the interval 0 < 2. 1) 2 cos 2 + cos - 1 = 0 2) sin

Solve each equation on the interval 0 ≤ θ < 2π.

1) 2 cos² θ + cos θ - 1 = 0

2) sin² θ - cos² θ = 1 + cos θ

3) tan θ = cot θ

4) 2 sin² θ - 5 sin θ + 3 = 0

5) sec² θ + tan θ = 0