(a) Prove the following: a i. (p'lxla) = in ap (p' la), ii. (Blxla) = / dp'd;(p')it a Pa(p ), ap where da(p') = (p'la) and ps(p') = (p'IB) are momentum-space wave func- tions. (b) What is the physical significance of ixE exp h where x is the position operator and E is some number with the dimension of momentum? Justify your