Complete the Function Table and Sketch the Graph

Every question gives you a quadratic function. Work out f(x) for each x in the table, then click those five points on the grid and the curve is drawn through them. Click a point again to take it away.

Here is how to do it:

Put the number from the top row in place of x and work the function out. Square first, then multiply, then add or subtract - $f(-3) = (-3)^2 + 4 \cdot (-3) + 1 = 9 - 12 + 1 = -2$.
Watch the sign. A negative number squared is positive, so $(-3)^2 = 9$ and not $-9$.
The five values are symmetrical about the middle one, because the middle x is the vertex of the parabola. If your first and last answers are not equal, one of them is wrong.
Look at the numbers on the y-axis before you plot. On the steeper parabolas the axis counts in twos.
A parabola never has a sharp corner at the bottom - the curve turns smoothly through the vertex.

Reload the page and you get a new worksheet - the functions are generated at random every time.