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 There are many different types of graphs.
All graphs must have certain features:
- A title
- Labelled axis indicating units used
- Even scales
Line Graphs
Line graphs show how quantities are changing. Below are four examples:
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This graph shows the water heating up steadily till it boils after 6 minutes.
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Notice the changes in the boy's height as he moves through his teenage years.
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The number of containers changes considerably from month to month.
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Line graphs are often used to show distance and time.
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Scatter Graphs
Scatter graphs are used to show connections between two quantities.Below are two examples:
There would appear to be a relationship between the mark and the time spent revising.
i.e. More revision − better mark!
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The graphs show that if the plane is new it is cheaper and that if it is faster it is bigger.
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Coordinate Graphs
Coordinate graphs are used to show a rule or relationships between x and y values. The points on the graphs below can be joined with straight lines.
Some terms to do with coordinate graphs are:
Domain The set of x-values (from the table).
Range The set of y-values (from the table).
Gradient Tells how steep a line is.
Intercept Where the lines cross the axes.
Below are two examples:
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This graph shows the relation x = 3. i.e. Each of the points has an x-value of 3.
This can be shown in a table:
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x
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3
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3
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3
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3
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3
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3
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3
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3
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3
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y
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0
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1
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2
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3
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4
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5
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6
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7
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8
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This graph shows the relation y = x + 2. i.e. Each of the y-values is 2 more than the x-value.
This can be shown in a table:
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x
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0
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1
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2
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3
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4
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5
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6
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y
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2
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3
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4
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5
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6
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7
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8
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Statistical Graphs
These graphs are detailed in Topic 45. |
