 Arcsin, arccos and arctan

 
In trigonometry one often needs to evaluate the reverse of sin, cos, and tan functions. This calc provides these functions, allowing you to find for example "what angle has a sin of 0.5".
 
It is important to remember that trigonometric functions are periodic, so for eample sin(x)=0 is true for x=0 rad, π rad, 2π rad, etc. Only the smallest positive result is returned here.  