3. Consider the following two wave equations x(t) = 2 sin (0,2nt - - ) + cos(0,4nt) 4 y(t) = 2e-0.2t cos(5xt) a. What is x(t)? If so. what is the fundamental frequency (in Hz)? b. Does x(t)? have a harmonic frequency? Explain from the equation! c. What is y(t)? If so. what is the fundamental frequency (in Hz)? d. Does y(t) have a harmonic frequency? Explain from the equation!4. The periodic signals x1(t) and x2(t) are expressed in the following equation -1, -1st