Confused on how the absolute value changes the method of deriving

[mathpat]

Homework Statement

Find derivative of abs (2x^3 + 8x^2 + 5x +1).

Homework Equations

The Attempt at a Solution

A little confused on how the absolute value changes the method of deriving that equation. When I derive it normally, I get (6x^2+16x+5).

 

[Office_Shredder]

It might help to do simpler examples that you can graph - compare the derivative of abs(x) to the derivative of x or x²-1 vs abs(x²-1)