Big Ideas Math Algebra 2, 2014
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Big Ideas Math Algebra 2, 2014 View details
8. Analyzing Graphs of Polynomial Functions
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Exercise 32 Page 217

A turning point is either a local maximum or minimum of the function. A zero is the x-coordinate of the point at which the graph intercepts the x-axis.

Turning Points: (-3,-1.5) and (0.5,-6.5)
Local Maximum: (-3,-1.5)
Local Minimum: (0.5,-6.5)
Real Zero: x=2.5
Least Possible Degree: 3

Practice makes perfect

We want to estimate the coordinates of every turning point. A turning point is either a local maximum or minimum of the function. Let's look at the given graph to see where the turning points are.

As we can see above, the graph has two turning points around (- 3,-1.5) and (0.5,-6.5). The point (- 3,-1.5) corresponds to local maximum and the point (0.5,-6.5) corresponds to local minimum.

Next, we will estimate the zeros of the function. A zero is the x-coordinate of the point at which the graph intercepts the x-axis. Let's consider the given graph.

The zero occurs at approximately x=2.5. Now, to find the least possible degree of the function, we will examine its end behavior.

We can see above that the end behavior is down and up. With this, we can make a conclusion about its degree. The degree must be an odd number. Also, the graph has 2 turning points. Therefore, the degree of the function must be greater than or equal to 3. With this in mind, we conclude that the possible degree of the polynomial is 3.

Turning Points (- 3,- 1.5) and (0.5,- 6.5)
Local Maximum (- 3,- 1.5)
Local Minimum (0.5,-6.5)
Real Zero x=2.5
Least Possible Degree 3