Choose the one alternative that best completes the statement or answers the question.
Find the exact value of the expression.
-$\cot ^ { - 1 } ( - 1 )$
A) $\frac { 2 \pi } { 3 }$
B) $\frac { 3 \pi } { 4 }$
C) $\frac { \pi } { 4 }$
D) $\frac { \pi } { 3 }$

Question

Quizplus · Accepted Answer

$\cot^{-1}(-1)$ corresponds to the angle whose cotangent is -1. The cotangent of an angle is -1 when the angle is $\frac{3\pi}{4}$ radians, which is in the second quadrant where cotangent is negative.

Choose the One Alternative That Best Completes the Statement or Answers