Page 18 - Mathematics Class - XII

ACTIVITY 1.4

OBJECTIVE

To demonstrate a function which is one-one but not onto.

MATERIAL REQUIRED
Y Cardboard
Y Some coloured chart paper

Y A pair of scissors
Y Some thumb pins / board pins
Y Sketch pen

Y Some pieces of thread or yarn or rubber band

PRE-REQUISITE KNOWLEDGE
1. Knowledge of relations.
2. Knowledge of functions and their types such as one-one and onto.

PROCEDURE
1. Take a cardboard and paste coloured chart paper cut outs of length 15 cm and width 5 cm on the left hand
side of the cardboard. Fix 4 board pins on it and name them 1, 2, 3 and 4 as shown in Fig. (a).
A

1 •
15 cm 2 •
3 •
4 •

5 cm
Fig. (a)

2. From other coloured chart paper, cut out another strip of length 12 cm and width 5 cm on the right hand
side of the cardboard as shown in Fig. (b) and fix 5 board pins on it and mark it x, y, z, u and v.

A B
1 •
• x
15 cm 2 • • y 12 cm
• z
3 •
4 • • u
• v
5 cm 5 cm
Fig. (b)

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