Find the DTFT of the following signals: a) x(n) = 3 au(n) b) y(n) = 3 nau(n) where "a" is a real, positive constant, so that |a|<1

> In an AM/DSB-LC modulator, the carrier signal is c(t) = 4 cos (6107 t) and the modulating signal is m(t) = cos(7000πt). The signal c (t) +m (t) is applied to the input of a nonlinear device whose characteristics given by i (t) = a₁v₁ (t) + a₂ v² (t) where a₁ and a₂ are positive constants. The output of the nonlinear device at a resistance R is passed through an ideal band pass filter with 3*107 Hz center frequency and 10500 Hz bandwidth to produce the modulated signal. If you know that the sideband power of the AM wave is half of the carrier power, find the ratio a₁/a2.

A discrete-time system has the following unit-pulse response, Find the response of this system y[n] when: x[n] = u[n]. h[n] = ((0.5)" (0.25)”)u[n]

Use graphical method to find the out of an LTI system with the given input and impulse response.         Please answer in typing format please ASAP for