Images file index

More ideas:

1. If e looks quadratic, its derivative should have one zero and be linear.
2. Looks quadratic, so its derivative should be linear (center graph). The zero of the derivative should be at the peak of b, which is a little to the right of zero.
3. Derivative of a linear function, as found in the center graph. Negative value corresponds to negative slope of the center graph.
4. Has 3 humps, so 3 places where its derivative is zero. Even. Derivative should be odd, and the 2nd derivative should be even.
5. Derivative of the function in the upper left corner should have two zeros, properly placed (where they occur for e!). e seems to have the right symmetry, and looks quadratic, like the derivative of a cubic (which the graph in the upper left corner appears to be).
6. Odd, as expected given d. Has proper number and placement of zeros, and appears cubic (so the 2nd deriv will appear quadratic).