Part-1
1. Create a length-224 sequence and find its DFT by using the 'fft' command in MATLAB. Determine the elapsed time of the calculation using 'tic' and 'toc' commands.
2. Repeat the previous problem for a length-(224-2000) sequence. Why is the elapsed time so different?
Part-2
3. Write a MATLAB program to calculate the DFT of a 2N-length real-valued sequence x[n] by only N-point FFT algorithms. Verify the correctness of the program for the following signals by comparing their DFT obtained from the above program and from using 2N-point FFT algorithm in MATLAB (plot the magnitude spectrum of both DFT results).
x[n] = 2cos(-3sin(11/43)n)