The set X of all possible input values is known as domain and the set of all values of f(x) as x varies through X is called range of a function.
Example: Let f : R → R be the function defined as f(x)= 2x+1 then find f -1(x)
Solution.
As 
→ (1)
we know that f( x ) = y
x = f -1(y)
By putting value of x in (1) we get
By Replacing y = x we get
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