Hii,

The answer to this will be:-

I=ml^2/12+mR^2/4I=ml212+mR^2/4

or I=m4(l23+R2)I=m4(l23+R2) -------------(1)

Also m=πR^2lp

=> R^2=m/πlp

Put in equation (1)

For maxima & minima

dIdl=m/4(2l3−m/πl^2ρ)=0

=> 2l/3=m/πl^2ρ=>2l/3=πR^2lρ/πl^2ρ

or 2l/3=R^2/l

=> l^2/R^2=3/2

or l^2R= root3/2

Hope this helps