Graphing Linear and Exponential Growth
Maths: Edexcel A Level Pure Maths, topic 6.2.3
Drawing Graphs of Exponential Growth and Decay
Exponential growth and decay can be plotted on a graph.
From a multiplier to a graph
- A multiplier for exponential growth or decay can be used to generate a table of values.
- A graph can then be plotted from the table of values.
Example question
- The population of a colony of bacteria increases by 2× every 2 weeks. The colony has a population of 50 at week 0.
- Plot a graph showing the exponential growth of the population.
Example answer
- Generate a table of values.
- shows the number of weeks.
- shows the population size.
Example answer cont.
- Plot these values on a graph.
Test yourself on Graphing Linear and Exponential Growth
The value of y grows exponentially by a multiplier of 1.3 for every increase of 1 in x. What are the values of A, B and C in the table?
The value of y grows exponentially by a multiplier of 1.45 for every increase of 1 in x. What are the values of A, B and C in the table?
The value of y decays exponentially by 32% for every increase of 1 in x. What are the values of A, B and C in the table?
The value of y decays exponentially by a multiplier of 0.9 for every increase of 1 in x. What are the values of A, B and C in the table?