(a) Draw the Equivalent model for 2-DOF vibratory system having Fixed-Free boundary conditions at its ends, and the mass m, m=2m and stiffness k, k-2k. Determine the natural frequencies and the mode shape for the given system. (b) List the methods for prediction of natural frequency of multi degree freedom system Discuss Raleigh's quotient method to determine upper bound frequency for the n-DOF vibratory (18, 12) system.