Question

Finding where a function is increasing, decreasing, or constant given the graph: Interval notation

Answer 1

We are asked to determine the intervals where the function is decreasing. To do that we need to remember that a funtion decreases when the output variable decreases as the input variables increases. Graphically, this can be seen where the graph has a negative slope. In this case, the function decreses in the interval:

`\lbrack-2,1\rbrack`

We use brackets to indicate that the extreme points of the interval are included in the interval.