Page 256 - Math Smart - 7

c) Mark any three points on the line that lie in the third quadrant.

The points shown are {-1, -1), (-3, -3) and {-4, -4).

2
■\
-♦•A-
5 4 - 3 2 1 M ; 1
-
-
-
(1
7
/\
s

d) The y-values of each point is the same as the A-vaiue of each point.
So, the equation of the line is = a-.
Check My
Understanding

O a) Complete the table of values for the equation _y = a + 1. X

3
X -3 -2 -1 0 1 2 3 2
y = A+ 1 -1 3 4 1
0
-1
b) Plot the points.
-2
Draw a line through the points with a ruler and label -3
the liney = A+ 1.

O a) Complete the table of values for the equation y = x + 2. X
3
A -3 -2 -1 0 1 2 3 2
y = A + 2 -1 3 5 1
0 + 2
b) Plot the points. -1
Draw a line through the points with a ruler and label -2
the line y = a + 2. -3

O Look at the straight lines you have drawn in Example 1 and Questions 1 to 2.
a) Write down two facts about the three lines y = a, y = a + 1 and y = A+ 2.
What are the similarities and differences between the lines?
b) Use these facts to draw the line v = a + 3.

Coordinate Geometry and Graphs