Trigonometry Examples

cos (510)

$\cos (510)$

Step 1

Remove full rotations of

360

$360$ ° until the angle is between

0

$0$ ° and

360

$360$ °.

cos (150)

$\cos (150)$

Step 2

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 (30)

$- \cos (30)$

Step 3

The exact value of

cos (30)

$\cos (30)$ is

\frac{\sqrt{3}}{2}

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

- \frac{\sqrt{3}}{2}

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

Step 4

The result can be shown in multiple forms.

Exact Form:

- \frac{\sqrt{3}}{2}

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

Decimal Form:

- 0.86602540 \dots

$- 0.86602540 \dots$