You can change the Functions that the integral is between and the Bounds of the Integral. The Swap buttons swap the two functions or bounds. Delete will delete the integral you are editing and you can change the colour of the shading.
The right hand Function is interesting as it allows you to find the integral between a function and the x axis or y axis. Just select from the list.
Show Area if Different allows for situations such as the integral of sin x from 0 to 2p. The integral is 0 but the area is 4. FX Graph can show this if you allow it.
