Answer
$125.47^{\circ}$
Work Step by Step
Ensuring that the calculator is in degree mode, we enter $\cot^{-1} (-0.7125586)$ as $\tan^{-1} (\frac{1}{-0.7125586})$ into the calculator and solve to the nearest hundred:
$\tan^{-1} (\frac{1}{-0.7125586})\approx-54.53^{\circ}$
Now adding the answer to $180^{\circ}$:
$-54.53^{\circ}+180^{\circ}=125.47^{\circ}$
Therefore, $\cot^{-1} (-0.7125586)=125.47^{\circ}$