3. The cantilever beam AB shown has an extension BCD attached to its free end. A force P acts at the end of the extension. a) Find the ratio a/L so that the vertical deflection of point B will be zero. b) Find the ratio a/L so that the angle of rotation at point B will be zero. c) For part b), determine the equation of the deflection curve for the cantilever beam AB. JA a PV B C