Use a reference triangle in an appropriate quadrant to find the angle.
-$\tan ^ { - 1 }$ (1)
A) $\frac { 3 \pi } { 4 }$
B) 0
C) $\frac { \pi } { 4 }$
D) 1

Question

Quizplus · Accepted Answer

We can use a reference triangle in the first quadrant, where opposite side is 1 and adjacent side is 1. Then, using the definition of tangent, we have:

$$	an 	heta = \frac{	ext{opposite}}{	ext{adjacent}}=\frac{1}{1}=1$$

Therefore, $	heta = \frac{\pi}{4}$ and the answer is choice C.

Use a Reference Triangle in an Appropriate Quadrant to Find tan⁡−1\tan ^ { - 1 }tan−1

Use a Reference Triangle in an Appropriate Quadrant to Find $\tan ^ { - 1 }$