Question

How do you evaluate `arcsin (-1/2)`?

Answer 1

find `arcsin (-1/2)`

Explanation:

`sin x = -1/2`--> find x ?

Trig table gives:

`sin x = -1/2` = sin (-30) = sin (360 - 30) = sin 330 -> x = 330 deg

Trig unit circle gives another arc x that has the same sin value `(-1/2)`:

x = 180 + 30 = 210 deg

Within period (0, 360), there are 2 answers: 210 and 330 deg