4. For a FM system with carrier frequency o, =27 x 10 rad/s, if the message signal is given by m(f) = Acos(27 x10*f) and the maximum frequency deviationA =27x10' rad/s, (a) determine the bandwidth of the FM signal; (b) If the amplitude of m(f) is doubled, what is the maximum frequency deviation now? Determine the bandwidth of the resulting FM signal; (c) If BOTH the amplitude AND frequency of m(f) are doubled, determine the bandwidth of the FM signal.