Trigonometry Examples

$5 \cos (- 30)$

Step 1

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant.

$5 \cos (30)$

Step 2

The exact value of $\cos (30)$ is $\frac{\sqrt{3}}{2}$ .

$5 \frac{\sqrt{3}}{2}$

Step 3

Combine $5$ and $\frac{\sqrt{3}}{2}$ .

$\frac{5 \sqrt{3}}{2}$

Step 4

The result can be shown in multiple forms.

Exact Form:

$\frac{5 \sqrt{3}}{2}$

Decimal Form:

$4.33012701 \dots$