Hints
1. The signal is heavily used in sampling.
2. It is an interpolating function, i.e., y(0) = 1, and y(k) = 0 for k ≠ 0 and $ \scriptstyle k\in\mathbb{Z}\, $
3. It will be used in this class later on.
4. It's name rhymes with something in your kitchen.
Answer
The signal is the (normalized) sinc function: $ \frac{sin(\pi x)}{\pi x} $
