Wedge 2 represents the volume enclosed by z=0, x=0, y=0, z=1-x^2, and y=1-x. The equations are printed on the model. The classic Multivariable Calculus problem asks one to express the volume of this volume using a triple integral in six different orders.
This model was designed and printed by my WLU summer research student Ryan McDonnell ('17). Details of the construction can be found at http://mathvis.academic.wlu.edu/2015/06/26/exercise-32/.
Update 2/26/2016: I've rescaled the model so it imports as a 9cm x 9cm x 9cm object.
You may have to scale by a factor of 10 if you're using MakerWare, since it tends to import files in mm, not cm. Object is sized to be 9cm in all dimensions, but smaller prints should work just fine.
This object was made on a MakerBot2X. We used the following settings:
0.20mm layer height
10% infill (hexagonal pattern)