$ x[n] = 2 + cos(\omega_0 n) + 4sin(\omega_0 n + \frac{\pi}{2}) $
where $ \omega_0 = \frac{2\pi}{N} $.
$ h[n] = x[n] * \delta[n] = \sum_{k=-\infty}^\infty x[k]\delta[n-k] $
$ h[n] = \bigg\{ \frac{x[n], when k = n}{0, else} $
