[RHSLilSweetie07]

Use group theory to determine whether the following integrals are non-zero (use the tables of direct products).

i) the overlap integral between a p_x orbital and a p_z orbital in the point group C_2v
ii) the overlap integral between a p_x orbital and a d_xz orbital in the point group C_3v
iii) the overlap integral between a p_y orbital and a d_z^2 orbital in the point group T_d
iv) the overlap integral between a p_z orbital and a d_z^2 orbital in the point group D_2h

I don't even know where to start.  Please help.