Trigonometry Examples

$- \frac{9 π}{4}$

Step 1

Add $2 π$ to $- \frac{9 π}{4}$ .

$- \frac{9 π}{4} + 2 π$

Step 2

The resulting angle of $- \frac{π}{4}$ is coterminal with $- \frac{9 π}{4}$ but isn't positive. Repeat the step.

$- \frac{π}{4}$

Step 3

Add $2 π$ to $- \frac{π}{4}$ .

$- \frac{π}{4} + 2 π$

Step 4

The resulting angle of $\frac{7 π}{4}$ is positive and coterminal with $- \frac{9 π}{4}$ .

$\frac{7 π}{4}$