Use periodic properties of the trigonometric functions to find the exact value of the expression.
-$\tan 9 \pi$
A) 0
B) 1
C) undefined
D) $- 1$

Question

Quizplus · Accepted Answer

The tangent function has a period of $\pi$, meaning $\tan(\theta) = \tan(\theta + n\pi)$ for any integer $n$. Therefore, $\tan(9\pi) = \tan(0)$ because $9\pi$ is an integer multiple of $\pi$. Since $\tan(0) = 0$, the correct answer is A.

Use Periodic Properties of the Trigonometric Functions to Find the Exact