Question

find reference angle cos(-300)

Explanation:

Step1: Use the property of cosine function

Since \(\cos(-\theta)=\cos\theta\), so \(\cos(- 300^{\circ})=\cos300^{\circ}\)

Step2: Determine the quadrant

\(300^{\circ}\) is in the fourth quadrant (\(270^{\circ}<300^{\circ}<360^{\circ}\))

Step3: Calculate the reference angle

The formula for the reference angle \(\alpha\) of an angle \(\theta\) in the fourth quadrant is \(\alpha = 360^{\circ}-\theta\). Substitute \(\theta = 300^{\circ}\), we get \(\alpha=360^{\circ}-300^{\circ}=60^{\circ}\)

Answer:

The reference angle of \(\cos(-300^{\circ})\) is \(60^{\circ}\)