9/1 Increasing, Decreasing, and Constant Intervals

9/1 Increasing, Decreasing, and Constant Intervals

Math Analysis Honors

​Ms. Kunkel

​Increasing, Decreasing, and Constant Intervals (over the domain)

• ​Always read intervals from left to right

• ​Always use parenthesis

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• ​Interval A: Increasing (0, 2)

• ​Interval B: Constant (2, 4)

• ​Interval C: Decreasing (4, 5)

• ​Interval D: Increasing (5, 8)

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• ​Increasing (0, 2) U (5, 8)

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​Increasing, Decreasing, and Constant Intervals (over the domain)

Constant (-5, -4) U (0, 1)

Decreasing (-4, 0) U (2, )

Increasing (1, 2)

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​A common mistake is to say the graph is increasing from -1 to +1. That would be reading along the

y-axis. Intervals are read over the domain, (x-axis) left to right only!

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Multiple Choice

When is the function decreasing?

• (30, 55)

• (40, 60]

• (15, 40)

• (60, -40)

Multiple Choice

When is this function increasing?

• (-3, 3)

• (-2.5, 2.5)

• [-3, 3]

• (3, ∞)

Multiple Choice

On which interval(s) is the given function increasing?

• (-∞, 2) U (-2, ∞)

• (-2, 2) U (-2, ∞)

• (-∞, -2) U (0.5, ∞)

• (0, 2) U (0.5, ∞)

Multiple Choice

Describe the interval(s) over which the given function is decreasing.

• (-∞, 0) U (2, ∞)

• (5, -4) U (0, -3)

• (-3, 0) U (2, 3)

• (2, 3)

Multiple Choice

How would you describe the behavior of this function on the domain interval (-1, 1)?

• increasing

• decreasing

• constant

Multiple Choice

Is interval 2 increasing, decreasing, or constant?

• Increasing

• Decreasing

• Constant

Multiple Choice

Is interval 3 increasing, decreasing, or constant?

• Increasing

• Decreasing

• Constant

Multiple Choice

Is interval 4 increasing, decreasing, or constant?

• Increasing

• Decreasing

• Constant

Multiple Choice

What is/are the increasing interval(s) for the function shown?

• $$\left(-3,\ 1\right)$$

• $$\left(4,\ 8\right)$$

• $$\left(-\infty,1\right)\ and\ \left(-3,\ 1\right)$$

Multiple Choice

What is the decreasing interval on the function shown?

• $$\left(-\infty,\ -3\right)$$

• $$\left(-\infty,\ -4\right)$$

• $$\left(-4,\ \infty\right)$$

• $$\left(-3,\ \infty\right)$$

Multiple Choice

What is the interval of decrease of this function?

• (1, ∞)

• (-∞, ∞)

• (2, ∞)

• None

​Week 4 Assignment

​Finish Questions 7-10 on the worksheet