Do the observables for d/dx and x^2 commute?

[user14]

Homework Statement

Are the observables corresponding to the d/dx and x^2 operators complementary?

Homework Equations

none

The Attempt at a Solution

I know that if the operators do not commute then their corresponding observables are complementary. I just don't know how to show mathematically that they don't commute.

 

[bp_psy]

Use the commutator definition [A,B]=AB-BA to show if they commute or not.