1. The problem statement, all variables and given/known data Sketch the graph of x ^ (4/9) * e ^ (-x) 2. Relevant equations None. 3. The attempt at a solution My y' = -x ^ (4/9) * e ^ (-x) ( 1 - 4/9x ^ 1/9). I keep on getting a reaaally long derivative for y'' and thus cannot place it on my sign table. Could someone please show me the correct steps in order to get a simplified y''?