Comment on Activity 4

1. A square is always nonnegative, and adding `1` makes the value at least `1.`
2. `tan theta` has vertical asymptotes at odd multiples of `pi text[/] 2`, so `tan^2 theta` must also.
3. At integer multiples of `pi`, `tan theta=0,` so the minimal value of the derivative (the smallest slope on the tangent graph) is `1.`

Your graph should be a series of U's, centered on the multiples of `pi.` Figure A1 shows the derivative (red) superimposed on the tangent function (blue).

Figure A1  The tangent function (blue) and its derivative (red)