= P7.21 Evaluate (*), for the ground state (n = 0) and first two excited states (n 1 and n 2) of the quantum har- monic oscillator. Use the hint about evaluating integrals given in Problem P7.6. is P7.6 Evaluate the average of the square of the linear momen- tum of the quantum harmonic oscillator, (px), for the ground state (n = 0) and first two excited states (n = = 1 and n = 2). = Hint: In evaluating integrals of this type, --- f(x) dx = 0 if - -00 . [ f(x) dx = 2 ["scu)dk 5. (xdx f(x) is an odd function of x and if f(x) is an even function of x