Checkpoint 8 Answers

1. `text[(]tan^(-1) t text[) (]sec^2 t text[)]+(tan t)/(1+t^2)`
2. All real numbers except odd multiples of `pi text[/] 2`.
3. 
4. The function (blue) is even, and its derivative (red) is odd. Both functions have vertical asymptotes at odd multiples of `pi text[/]2.` The derivative is `0` where the function has a horizontal tangent (at the origin). The derivative has a maximum negative value where the function has a maximum negative slope, and similarly with minimal positive values.