The wave functions for a particle restricted to lie in a rectangular region of length "p" and "q" (a particle in a two-dimensional box) are:
Έ_nx,ny(x,y) = (4/pq)^1/2 sin(nxΑx/p) sin(nyΑy/q)
Where, 0 ≤ x ≤ p and 0 ≤ y ≤ q. Show that these wave functions are normalized.