Answer
a. See graph, red curve.
b. See explanations.
c. See graph, blue curve.
Work Step by Step
a. See graph, red curve.
b. Using the horizontal line test for the graph, we can see that there will be only one intersect for any horizontal line; thus the restricted secant has an inverse function.
c. As $y=cot^{-1}(x)$ is a reflection of $y=cot(x)$ around $y=x$, we can graph the inverse (blue curve) as shown in the figure.
