From $\tan\varphi = -3/2 = -1,5$ to $\varphi\approx 123,69^\circ$

Question

Sorry for this question but what do I have to type into my counter to come from

$$\tan \varphi = -1,5 $$

to $\approx 123,69^\circ$ and $\approx 303,69^\circ$? Thanks!

Answer 1

To solve for $\theta$ you can use $\arctan(-3/2) = -\arctan(3/2)$.

To convert from radians to degrees, you multiply by $\frac{180^\circ}{\pi}$: $$x\text{ radians} \times \dfrac {180^\circ}{\pi} = y^\circ$$