Graphing exponential decay

When graphing exponential decay, it is always a good idea to make a table of values and you could look for at least 5 points that you can use to make the graph. In the table below, we use 6 points.

It is also a good idea to choose both negative and positive values for x, especially numbers that are opposites. For example, notice how we chose x = -1 and x = 1.

Graph y = 20 × 0.5x

x
20×0.5x
(x, y)
-2
20×0.5-2 = 20 / 0.52 = 20/0.25 = 20 / (1/4) = 20 × 4 = 80
(-2, 80)
-1
20×0.5-1 = 20 / 0.51 = 20/0.5 = 20 / (1/2) = 20 × 2 = 40
(-1, 40)
0
20×0.50 = 20 × 1 = 20
(0, 20)
1
20×0.51 = 20 × 0.5 = 20 × 1/2 = 10
(1, 10)
2
20×0.52 = 20 × 0.25 = 20 × 1/4 = 5
(2, 5)
3
20×0.53 = 20 × 0.125 = 20 × 1/8 = 2.5
(3, 2.5)


In the graph below, each square along the x-axis represents 1 unit and each square along the y-axis represents 10 units. Notice that for an exponential decay, as x increases, y decreases exponentially or decreases rapidly.

Graph of exponential decay



Recent Articles

  1. How to Derive the Equation of an Ellipse Centered at the Origin

    Mar 13, 19 11:50 AM

    Learn how to derive the equation of an ellipse when the center of the ellipse is at the origin.

    Read More

New math lessons

Your email is safe with us. We will only use it to inform you about new math lessons.

            Follow me on Pinterest


Math quizzes

 Recommended

Scientific Notation Quiz

Graphing Slope Quiz

Adding and Subtracting Matrices Quiz  

Factoring Trinomials Quiz 

Solving Absolute Value Equations Quiz  

Order of Operations Quiz

Types of angles quiz


Tough algebra word problems

Tough Algebra Word Problems.

If you can solve these problems with no help, you must be a genius!

Recent Articles

  1. How to Derive the Equation of an Ellipse Centered at the Origin

    Mar 13, 19 11:50 AM

    Learn how to derive the equation of an ellipse when the center of the ellipse is at the origin.

    Read More

K-12 math tests


Everything you need to prepare for an important exam!

K-12 tests, GED math test, basic math tests, geometry tests, algebra tests. 

Real Life Math Skills

Learn about investing money, budgeting your money, paying taxes, mortgage loans, and even the math involved in playing baseball.