Trigonometry Examples

$\cos (- \frac{4}{5})$

Step 1

Since $\cos (- \frac{4}{5})$ is an even function, rewrite $\cos (- \frac{4}{5})$ as $\cos (\frac{4}{5})$ .

$\cos (\frac{4}{5})$

Step 2

The result can be shown in multiple forms.

Exact Form:

$\cos (\frac{4}{5})$

Decimal Form:

$0.69670670 \dots$