so, u wanna find the range from the function....

The simplest way is to write down/construct the graph from the function, the range of the is the interval of y-axis that fit the graph.

example:

-the range (S) for the graph is (0,inf)

and to find the inverse from the function,

1)

let,

the objectives to arrange the function until you get the equation for x=...

........hope it help..........