How to calculate inverse of trigonometric functions ?

[Kartik Domadiya]

How do we find inverse of trigonometric functions ?.. I find sin'(x),
cos'(x) and tan'(x) functions and I guess that its for finding inverse
values. Here is what i get
In arity
tan'(1) = 3.42551882
In other calculators
tan-1(1)=45 degrees
tan-1(1)= 0.7853981634

I want something similar to arcsin(x), arccos(x) and arctan(x)
functions which are in java.

My only question is how do we find inverse of trigonometric functions ?

[Kartik Domadiya]

I explored e.thing in this arity.jar and got to know all functions
that calculates inverse trigonometric functions. It was mentioned here
http://calculator.javia.org/

Here are functions for calculating inverse trigo. func.

asin(x)
acos(x)
atan(x)