SOLUTION: what is the inverse function of y=3x^3-9 including steps?

General strategy: solve for x then swap x & y at the very end.



              <--- added 9 to both sides

           <--- divided both sides by 3

   <--- took cube root of both sides



   <--- re-wrote w/x on left hand side



Now swap x & y:

  <--- this is the inverse function





Check...

You can check it by computing  ... it should give you x back.

We plug in '' for 'x' in the inverse function:

 (ok)