Precalculus Examples

$\cos (120)$

Step 1

Find the value using the definition of cosine.

$\cos (120) = \frac{adjacent}{hypotenuse}$

Step 2

Substitute the values into the definition.

$\cos (120) = \frac{- \frac{1}{2}}{1}$

Step 3

Divide $- \frac{1}{2}$ by $1$ .

$- \frac{1}{2}$

Step 4

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