year 8 maths

402 Chapter 7 Linear relationships 1
Example 1
Plotting points
Draw a number plane extending from −4 to 4 on both axes, then plot and label these points.
a A(2, 3) b B(0, 4) c C(−1, 2.5)
d D(−3.5, 0) e E(−2, −2.5) f F(2, −4)
SOLUTION
y
4 B
3 A
C
2
1
D
−4 −3 −2 −1
O
−1
1 2 3 4
−2
E
−3
−4 F
x
EXPLANATION
The x -coordinate is listed first followed by the
y -coordinate.
For each point start at the origin (0, 0) and move
left or right or up and down to suit both x - and
y -coordinates.
For point C(−1, 2.5) , for example, move 1 to the
left and 2.5 up.
Exercise 7A
UNDERSTANDING AND FLUENCY
1–3, 4(½) 3, 4(½), 5a
4(½), 5b
1 Refer to the Key ideas and complete each of the following sentences.
a The coordinates of the origin are .
b The vertical axis is called the -axis.
c The quadrant that has positive coordinates for both x and y is the quadrant.
d The quadrant that has negative coordinates for both x and y is the quadrant.
e The point (−2, 3) has x -coordinate .
f The point (1, −5) has y -coordinate .
2 Write the missing number for the coordinates of the points a – h .
y
g(—, 3)
f(–3, —)
−4 −3 −2
e(—, –1)
4
3
2
1
−1
O
−1
−2
−3
−4
h(—, 2)
1 2 3 4
c(1, —)
d(—, –4)
a(3, —)
x
b(3, —)
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
Photocopying is restricted under law and this material must not be transferred to another party.