Precalculus Examples

cos (- \frac{π}{7})

$\cos (- \frac{π}{7})$

Step 1

Add full rotations of

2 π

$2 π$ until the angle is greater than or equal to

0

$0$ and less than

2 π

$2 π$ .

cos (\frac{13 π}{7})

$\cos (\frac{13 π}{7})$

Step 2

The result can be shown in multiple forms.

Exact Form:

cos (\frac{13 π}{7})

$\cos (\frac{13 π}{7})$

Decimal Form:

0.90096886 \dots

$0.90096886 \dots$

⎡ ⎢ ⎣ \begin{matrix} x^{2} & \frac{1}{2} \sqrt{π} & \int x d x \end{matrix} ⎤ ⎥ ⎦

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