Please use MATLAB to answer this question. Please provide the code as well as the graphs, Thank you!

Please do not reuse any answers for this question. Thank you!

I know there is answers for part a and b but please make sure to include the answers for part c and d as well please.

2. Zero- and first-order holds a) Given the continuous waveform x(t)= 20 cos(407t), sample a single period at the Nyquist rate to obtain x[n]. Display x(t) and x[n] on the same plot. b) Up-sample by a factor of 4 (use the Matlab routine upsample). This should insert three zeros in-between each of the original samples of x[n]. c) Apply a 4-element zero-order hold filter to this up-sampled sequence. Display the original continuous time signal, the original samples, and the results of the zero-order hold, all on the same plot. d) Create a first-order hold using an autoconvolution of the zero-order hold and repeat part c. 2. Zero- and first-order holds a) Given the continuous waveform x(t)= 20 cos(407t), sample a single period at the Nyquist rate to obtain x[n]. Display x(t) and x[n] on the same plot. b) Up-sample by a factor of 4 (use the Matlab routine upsample). This should insert three zeros in-between each of the original samples of x[n]. c) Apply a 4-element zero-order hold filter to this up-sampled sequence. Display the original continuous time signal, the original samples, and the results of the zero-order hold, all on the same plot. d) Create a first-order hold using an autoconvolution of the zero-order hold and repeat part c