How do you evaluate arcsin(sin3)?

1 Answer
Aug 21, 2015

arcsin(sin(3))=π3

Explanation:

Note that arcsin maps [1,1] to [π2,π2].

We need to find an angle x[π2,π2] where sin(x)=sin(3).

Since sin(x) is symmetric about x=π2 we have sin(3)=sin(π3). π3 is in [π2,π2], therefore we have:

arcsin(sin(3))=π3