Question

evaluate \\( \cos ( - 60 ^ { \circ } ) \\) exactly.
note: enter the exact, fully simplified answer.
\\( \cos ( - 60 ^ { \circ } ) = \\)

Explanation:

Step1: Use the property of cosine function

The cosine function is an even function, so $\cos(-\theta)=\cos\theta$.
$$\cos(-60^{\circ})=\cos60^{\circ}$$

Step2: Recall the value of $\cos60^{\circ}$

We know that $\cos60^{\circ}=\frac{1}{2}$.

Answer:

$\frac{1}{2}$