I need help on inverse function

Question

g (x)=x+1

Answer 1

The easiest, and perhaps the only way, to solve this kind of problems is to write

 

y = g(x) = x+1  

 

and solve this equation as a function of y, i.e., 

x = y-1.

 

Therefore, the inverse function you are looking for is given by g^-1(x) = x-1. 

You can always check that you got the right answer as follows:

 

g^-1(g(x))  g^-1(x+1) = (x+1)-1 = x  which shows we chose the right g^-1.