Page 133 - Mathematics

y

y N(x , y )
2 1 2 Tanzania Institute of Education

y
1 P(x , y )
1 1

0 x 1 x

Figure 6.4: A vertical line PN with undefined gradient

The gradient of the line joining the two points P( , )xy and N( , )xy can be
1
1
2
1
obtained as follows:
y − y
m = 2 1 .
x − x 1
2
But x = x 2 and y ≠ 2 . y It implies that,
1
1
y − y
m = 2 1
x − x 1
1
y − y
= 2 1
0
Mathematics Form One
Note that, there is no real answer when a number is divided by 0. This is
generally referred to as undefined. Since the gradient of PN is undefined, then

the line PN is vertical.

127

Mathematics form 1.indd 127
25/10/2024 09:51:47
Mathematics form 1.indd 127 25/10/2024 09:51:47