Precalculus Examples

$\cos (\frac{4 π}{5})$

Step 1

The result can be shown in multiple forms.

Exact Form:

$\cos (\frac{4 π}{5})$

Decimal Form:

$- 0.80901699 \dots$

$[\begin{array}{c} x^{2} & \frac{1}{2} \\ \sqrt{π} & \int x d x \end{array}]$