Worked example Find the distance between the points (–2, 1) and (4, 9).
Solution x y1
x y y 4 − 2 9 1
9 8
4 7
3 6
2 5
A (–2, 1)
1 –2 –1 0
6 1 2 3 4 B (4, 9)
8
x
Practice questions 31.2
1. Calculate the distance between each of the following pairs of points. Give your answer correct to two decimal places where necessary. (i) (1, 3) and (5, 7) (ii) (10, 6) and (1, –4)
(iii) (3, 2) and (8, 2) (iv) (–8, –9) and (–4, –10)
(v) (9, –3) and (–1, 8) (vi) (–7, –2) and (6, 9)
2. Find the length of each of the following line segments. Give your answer correct to two signifi cant fi gures where necessary.
(i) –5 –4 –3 –2 –1 y
1 0
–1
–2 –3 –4 –5
–6 –7
(iv) y 5
4 3 2 1
–5 –4 –3 –2 –1 0 –1
–2 –3
492 Linking Thinking 1 1 2 x –3 –2 –1 (v) 1 x (ii) y