Foundation and Higher · real-life graphs

Real-life graphs.
Read the axes
first.

the gradient always
means something

on any graph in context —

Gradient

the gradient is a rate

y units per x unit

graph 1 of 4

Conversion graphs

1. £20: go up to the line, then across.

2. Read the other axis: $25.

✓ £20 = $25

graph 2 of 4

Off the graph? Scale up

1. £200 is not on the axis.

2. £200 = 10 × £20, so 10 × $25.

✓ £200 = $250

graph 3 of 4

A fixed charge

1. The line starts at £3: the fixed charge.

2. Then it rises £2 for every mile.

✓ Intercept = fixed, gradient = rate

graph 4 of 4

Filling a container

1. Narrow: the depth rises quickly. Steep.

2. Wide: the depth rises slowly. Shallow.

✓ Narrowing? The line curves upwards

real-life graphs —

Axes

read the labels and the scale

Intercept

the starting value

Gradient

the rate: steeper means faster

One square is not always 1.
Check the scale.

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