@cin123,
Hopefully you are comfortable with functions at this point. A function has an input value that maps to an output value. The
inverse of that function is the reverse, it is asking what input would be required to get the desired output value... in over words it maps the original output value to an input value.
Let's take a simpler example; f(x) = 3 + x.
You should be able to write a table of input values to output values.
Code:
Input Output
x f(x)
----- ---------
0 3
1 4
2 5
So an input value of "0" maps to an output value of "3", and "1" maps to "4" and so on. (Tell me if this isn't crystal clear).