how do i use the trig inverse keys?

I have included this post in the reference material sticky post.  

There are a number of ways.

Say I want

$$tan^{-1}16 \qquad$ where the 16 is in degrees$$ $

I can enter it in the input line as     tan^-1(16)=       or as         atan(16)

or using the keys I'd press  [2nd] [asin] 16 = 

asin stands for arc sine and arc sin means the same as inverse sine