The impulse response of an LTI system is given as:
$h[n]=\left\{ \begin{array}{rcl} \frac{\omega_c}{\pi} & n=0\\ \frac{\sin \omega_cn}{\pi n} & n\neq 0 \end{array}\right.$
It represents an ideal
- non-casual, low-pass filter
- casual, low-pass filter
- non-casual, high-pass filter
- casual, high-pass filter