Question

What values between $0^o$ and ${360}^o$ may $A$ have when
$\tan A=-1$

Answer 1

$\tan A=-1$

When $A$ is in second quadrant $\angle A={180}^{\circ }-{45}^{\circ }={135}^{\circ }$

When $A$ is in fourth quadrant $\angle A={360}^{\circ }-{45}^{\circ }={315}^{\circ }$

In first and third quadrants $\tan A=-1$ will not be satisfied.$\because \tan A$ is positive in first and third quadrants.