Page 10 - Spotlight A+ SPM Additional Mathematics Form 4 & 5

Form
4 Additional Mathematics Chapter 1 Functions

13. The continuous function is a function where
CHAP the points on the graph are connected by a Example 2
1 straight line of curve. By using function notation, express f in terms of

f(x) x for each of the following relations.
(a) f
–4 1
2 7
5 10
7 12
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(b) f
x x y
0
–2 •
–1 • • 1
Example 1 1 • • 4
2 •
Determine whether the following relation is a
function or not. Justify your answer.
(a) Solution:
• 10 (a) f : x → x + 5 or f(x) = x + 5
3 • 2 2
• 16 (b) f : x → x or f(x) = x
5 •
• 60 Try question 2 in Formative Zone 1.1
7 •
• 62

(b) Example 3
–1 • By using vertical line test, determine whether
• 1
2 • each of the following graphs is a function or not.
• 4
4 • (a) (b)
• 36 y y
6 •

(c)
• 3 2 x
p • 0
• 6 x
q • 0 2
• 9
r • Solution:
• 12
(a)
(d) y
• 10
10 • Vertical line test
• x
20 •
• y 2
30 •
• z x
0 2
Solution: The graph is a function.
(a) The relation is a function because each (b)
object has only one image. y Vertical line test
(b) The relation is not a function because there
is one object does not have any image.
(c) The relation is not a function because there x
is one object that has two images. 0
(d) The relation is a function because each
object has only one image. The graph is not a function.
Try question 1 in Formative Zone 1.1 Try question 3 in Formative Zone 1.1

4 1.1.1