how do i take 64 samples from a sine wave and perform 256 point DFT on that?

Hi , I am supposed to take 64 samples from a sine wave and perfrom 256 point DFT how can i do that..

please check if this code is correct

%%%%%%%%%%%%%%%
Fs = 30; % Sampling frequency
t = 0:1/Fs:1; % Time vector of 1 second
n = 64;
f = 8;
x = cos(2* pi*t*f*n);

Answer 1

[Rick Rosson]

   Fs = 30;
   dt = 1/Fs;
   N = 64;
   t = dt*(0:N-1)';
   Fc = 8;
   x = cos(2*pi*Fc*t);
   M = 256;
   ...
   ...

Answer 2

[Rick Rosson]

   >> doc fft
   >> doc fftshift