So my teacher is bad at explaining so I need your help.

1. If cosθ = and 0 ≤ 2θ ≤ , find sin θ.

2. Find all θ in the interval [0,2) that satisfy the equation: sinθ = .

Number 2 is suppose to be:

Find all θ in the interval [0,2) that satisfy the equation:

Tips are kind of helpful, but step-by-step views will surely help in understanding it thoroughly...

Thank You!