Okay you got,Originally Posted by margaritas
Since you are working with absolute value, you need to divide the the intervals were the function is below the x-axis and above the x-axis. (Look at graph below without absolute value)
Therefore, the point where this change happens is at zero.
Thus you can set up your integral as,
(Note the negative sign in front of the integral because since it is below the intregral is going to be negative and you need it to be positive cuz you have absolute value).