cos(0°) find reference angle

Explanation:

Step1: Analyze the angle

The angle (0^{\circ}) is in the first - quadrant.

Step2: Recall the formula for reference angle

For an angle (\theta) in the first - quadrant ((0\leq\theta\leq90^{\circ})), the reference angle (\theta_{r}=\theta).

Answer:

The reference angle of (0^{\circ}) is (0^{\circ})