Page 15 - Mathematics Class - XII

ACTIVITY 1.3

OBJECTIVE
To demonstrate a function that is not one-one but is 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 as 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 3 board pins on it. Mark it x, y and z.

A
B
1 •
15 cm 2 • • x 12 cm
• y
3 •
4 • • z

5 cm 5 cm

Fig. (b)

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