Question

Which of the following statement(s) describes the rate of change of f over the interval 1.5 ≤ x ≤ 3? Select all that apply.

Answer 1

2 Answers: Choice B and Choice C

The rate of change is 2.

The rate of change is constant.

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Explanation:

The first point on the left is when x = 1.5 and it has a height of y = 1

The point (1.5, 1) is on the line.

So is the point (3,4) for similar reasoning.

Compute the slope between those points

m = (y2-y1)/(x2-x1)

m = (4-1)/(3-1.5)

m = 3/(1.5)

m = 2

The slope is 2, which is the same as saying the rate of change is 2. This only applies when x > 1 of which the interval 1.5 ≤ x ≤ 3  is a part of.

Since the slope stays at 2 on the interval 1.5 ≤ x ≤ 3, this means we consider the slope to be constant. If the curve bended at all on this interval, then it wouldn't be a constant slope.