EDXers!!! Plz help with MITx 8.01x

I don't know how to solve HW8 Problem 3 Question c)
Can anybody help me???? Explain Plz

Tr=m*g+(2*m*b)/pi*((2*l)/(1/2*m*R^2)*(m*g)/(1+(m*b^2)/(1/2*m*R^2)))