I have been using Maple for sometime as its document interface feels nicer and more friendly than mathematica's . I have never been able to plot arrows in Mathematica or use indices efficiently. I am more of a curious self teaching physics person. But I just found something interesting when calculating the potential produced by a charge placed outside of a conducting grounded sphere. This example is fully worked out by Jackson - Section 2.2 - Eqs 2.1 to 2.5. In my numerical example the charge q= 1 Coulomb is placed at the coordinates <0.2 m, 0.2 m, 0.3 m> . The sphere has radius 0.1 m. It happens that on the sphere, say at <0 m, 0 m, 0.1 m>, the potential should be zero but Maple evaluates it to 10/Pi ~ 3.18 and Mathematica evaluates it to 0.0000114441. On the other hand PocketCas for IOS 10 is giving me exactly zero! Has anyone seen this kind of problem? Would I making any dumb mistakes ?