2. A polynomial function is quadratic if it has a single variable and its highest degree is 2.
3. y = x²
This is about the simplest quadratic function. It can be graphed fairly easily by choosing points symmetrically about x=0, such as x = ±1, ±2, and so on. Plot the points, and draw a smooth curve through them.
(x, y) = (0, 0), (±1, 1), (±2, 4), (±3, 9)
