Trigonometry Examples

$3 \cos (- \frac{π}{2})$

Step 1

Add full rotations of $2 π$ until the angle is greater than or equal to $0$ and less than $2 π$ .

$3 \cos (\frac{3 π}{2})$

Step 2

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

$3 \cos (\frac{π}{2})$

Step 3

The exact value of $\cos (\frac{π}{2})$ is $0$ .

$3 \cdot 0$

Step 4

Multiply $3$ by $0$ .

$0$