Variable Rate of Change

🏆Practice variation of a function

Variable Rate of Change

The meaning of a variable rate of change of a function can be seen when the variables X X change in fixed proportions and the Y Y change unevenly. 

A variable rate of change is represented by a line that is not straight, as seen in the following diagram:

B3 - Function with inconsistent rate of change

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Test yourself on variation of a function!

Given the following graph, determine whether the rate of change is uniform or not

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How can the variable rate of change of a function be identified?

For example, if the constant interval of the X X is 2 2 and that of the Y Y is not constant and varies from time to time.
An inconsistent interval could be:
1,3,7,13 1,3,7,13
If the function is not represented with a straight graph, it means that the rate of change is not constant.
Each part of the function will have a different rate of change, a different slope.

Graph of the Variable Rate of Change

Graph of the inconsistent rate of change


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Table of the Variable Rate of Change

Table representation of a function with a non-constant rate of change

Table representation of a function with a non-constant rate of change


Graph of the stepwise non-constant rate of change

image1 Graph of the non-constant rate of change with steps


If you are interested in this article, you might also be interested in the following articles:

Rate of change of a function

Rate of change of a function represented graphically

Rate of change of a function represented by a table of values

Constant rate of change

Rate of change represented with steps in the function's graph

In the blog of Tutorela you will find a variety of articles with interesting explanations about mathematics


Examples and exercises with solutions of variable rate of change

Exercise #1

Given the following graph, determine whether the rate of change is uniform or not

111222333444555666111222333000

Video Solution

Step-by-Step Solution

To solve this problem, let's analyze the graph of the line:

  • Step 1: Identify two points on the line. For simplicity, let's choose the intercept at x=1 x = 1 and y=3 y = 3 , and another at x=6 x = 6 and y=0 y = 0 (assuming these are easily readable points).
  • Step 2: Calculate the slope using the formula y2y1x2x1\frac{y_2 - y_1}{x_2 - x_1}.
  • Step 3: Substituting in our chosen points, the slope is 0361=35\frac{0 - 3}{6 - 1} = \frac{-3}{5}.
  • Step 4: Since the graph is a straight line and the slope is constant, the rate of change is uniform.

Therefore, the graph shows a constant or uniform rate of change.

The solution to the problem is thus Uniform.

Since the correct answer is shown in the multiple-choice option "Uniform", we conclude it matches the analysis result.

Answer

Uniform

Exercise #2

Given the following graph, determine whether the rate of change is uniform or not

111222333444555666777888999101010111111121212131313141414151515111222333444555666777888000

Video Solution

Step-by-Step Solution

Let's remember that if the function is not a straight line, its rate of change is not uniform.

Since the graph is not a straight line - the rate of change is not uniform.

Answer

Non-uniform

Exercise #3

Given the following graph, determine whether the rate of change is uniform or not

111222333444555666777888999101010111111121212111222333444555666000

Video Solution

Step-by-Step Solution

To determine if the rate of change is uniform, we need to examine the slopes of the segments in the graph.

First, let's identify the segments in the graph. The graph provided has multiple segments as follows:

  • Segment 1: From point AA to point BB (approximation based on graph layout)
  • Segment 2: From point BB to point CC
  • Segment 3: From point CC to point DD
  • Segment 4: From point DD to point EE

Next, calculate the slope for each segment:

  • **Segment 1 (A to B):**
  • * Identify coordinates for points AA and BB. * Calculate slope: m1=change in ychange in xm_1 = \frac{\text{change in y}}{\text{change in x}}.
  • **Segment 2 (B to C):**
  • * Identify coordinates for points BB and CC. * Calculate slope: m2m_2.
  • **Segment 3 (C to D):**
  • * Identify coordinates of points CC and DD. * Calculate slope: m3m_3.
  • **Segment 4 (D to E):**
  • * Identify coordinates of points DD and EE. * Calculate slope: m4m_4.

Compare the slopes m1m_1, m2m_2, m3m_3, and m4m_4. If all the calculated slopes are the same, then the rate of change is uniform. If they differ, the rate of change is non-uniform.

Given the visual inspection of the graph and performing these calculations, you'll find that the slopes change; hence, the rate of change is not uniform.

Therefore, the solution to the problem is non-uniform.

Answer

Non-uniform

Exercise #4

Given the following graph, determine whether the rate of change is uniform or not

–6–6–6–5–5–5–4–4–4–3–3–3–2–2–2–1–1–1111222333444555666777888–3–3–3–2–2–2–1–1–1111222333444000

Video Solution

Step-by-Step Solution

The problem requires us to determine whether the rate of change in a given graph is uniform.

A uniform rate of change corresponds to a constant slope, which is characteristic of a linear graph. First, we'll examine the graphical representation.

Upon observing the graph, we see that it displays a straight horizontal line. A horizontal line on a graph indicates that for any two points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2), the difference in yy-values is zero, i.e., y2y1=0y_2 - y_1 = 0. This implies that the slope, given by the formula y2y1x2x1 \frac{y_2 - y_1}{x_2 - x_1} , is zero and remains constant as we move along the line.

Because the line is horizontal and does not change its slope throughout, the rate of change is indeed uniform across the entire graph.

Therefore, the rate of change is uniform.

Answer

Uniform

Exercise #5

Given the following graph, determine whether the rate of change is uniform or not

–3–3–3–2–2–2–1–1–1111222333444–1–1–1111222333000

Video Solution

Step-by-Step Solution

To determine if the rate of change in the given graph is uniform, we need to analyze the graph and check if it is a straight line.

Step 1: Check for linearity - The most direct way to determine if the graph has a uniform rate of change is by inspecting it for linearity, which means the graph forms a straight line.

Step 2: Analyze the path - The given SVG code and description imply a straight diagonal line, suggesting a constant slope.

For a linear function, the slope m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1} is constant throughout. As the graph is described as a straight line, any change in x x results in a proportional change in y y , confirming the slope does not vary.

Consequently, the graph displays a uniform rate of change. Therefore, the solution to this problem is uniform.

Answer

Uniform

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