The Attempt at a Solution
I understand the solution of the problem, but I want to know why don't my approach work.
I didn't change the frame of reference.
I use the regular method of solving a torque problem.
(mgsinθ - mAcosθ)(L/2) = mL2/3 θ''
which is approximately equal to
gθ-A = 2/3 L θ''
by solving differential equations, I got a frequency of Root (3/2 * g/L) , why am I wrong? Thank you (Also, isn't the moment of inertia of a rod 1/3 * mL^2 with respect to the rod?)