Question: how to do sin x=0.3?
Answer: Since sine is periodic with period 2 pi, we can add any number of 2 pi's to our two answers. So all the angles that satisfy sin(x) = 0.3 are: x ≈ 0.30469 + n(2 pi) and x ≈ 2.83690 + n(2 pi); where n is any integer.