Precalculus Examples

$\sin (870)$

Step 1

Remove full rotations of $360$ ° until the angle is between $0$ ° and $360$ °.

$\sin (150)$

Step 2

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

$\sin (30)$

Step 3

The exact value of $\sin (30)$ is $\frac{1}{2}$ .

$\frac{1}{2}$

Step 4

The result can be shown in multiple forms.

Exact Form:

$\frac{1}{2}$

Decimal Form:

$0.5$