so it is by considering -just for instance -that we are working with 4 rods ...
each of which is at distance dr as r changes from 0 to a/2 in two cases and from 0 to b/2 in the other two cases...
by adding them we get :
I=\intr^2.dm
r2=x2+y2
therefore I=\int(x2+y2)dm
Iz=Iy+Ix
((all...