Compute each part of given problem:
Problem: A 5.1 cm x 3.8 cm rectangle lies in the xz-place.
Part A: What is the electric flux through the rectangle if E = (100i+40k)N/C?
Part B: What is the electric flux through the rectangle if E = (100i+40j)N/C?
Please show all intermediate steps and formulas for above problem.