Algebra Examples

$\cos (π)$

Step 1

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the second quadrant.

$- \cos (0)$

Step 2

The exact value of

$\cos (0)$ is

$1$ .

$- 1 \cdot 1$

Step 3

Multiply

$- 1$ by

$1$ .

$- 1$

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