Trigonometry Examples

cos (180 °)

$\cos (180 °)$

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

$1$ .

$- 1$

$\cos 180 °$

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√

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≥

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≤

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