Using the graph below, determine the intervals of increasing/decreasing and where the function is positive/negative.
Solution
The function is represented with tailing ends (not fixed endpoints) so we can presume that the domain is \((-\infty,\infty)\). With that in mind:
\[ \begin{{array}}{r|l} \text{Increasing:}&(5.5,10.5)\\ \hline \text{Decreasing:}&(-\infty,5.5)\cup(10.5,\infty)\\\hline \text{Positive:}&(-\infty,3)\cup(8,13)\\ \hline \text{Negative:}&(3,8)\cup(13,\infty) \end{{array}} \]