Question

How to get the value of α in the formula?
$\alpha \: = {tan}^{ - 1} ( \frac{y}{x} )$
I mean specific values like 40° or 65.25°.
Thanks.

Answer 1

Specific values like tan^-1 (3/4)=37°. tan^-1 (4/3)=53° are important.

you will also get values like sin^-1(3/5) etc,these all are gained from one triangle.see in the image.

this is the only important triangle to find some values.you don't need to remember other values