Page 34 - Mathematics Class - XI

ACTIVITY 3.3

OBJECTIVE
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To plot the graphs of sin x, sin 2x, 2 sin x and sin using same coordinate axes.
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MATERIAL REQUIRED
 Hardboard  Graph paper  Different coloured pencils
 White chart paper  Ruler  Glue

PRE-REQUISITE KNOWLEDGE
1. Knowledge of plotting a graph 2. Knowledge of trigonometric ratios

PROCEDURE
1. Take a hardboard of convenient size and paste a white chart paper on it.
2. Paste a graph paper on the chart paper.
3. On the graph paper, draw two mutually perpendicular X′OX and YOY′, intersecting each other at the point
O. These perpendicular lines are known as coordinate axes.

Fig. (a)
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4. Prepare the table of ordered pairs for sin x, sin 2x, 2 sin x and sin for different values of x shown in the
table below. 2

p p p p 5p p 7p 2p 9p 5p 11p
T. ratios 0º p
12 6 4 3 12 2 12 3 12 6 12

sin x 0 0.26 0.50 0.71 0.87 0.97 1.00 0.97 0.87 0.71 0.50 0.26 0

sin 2x 0 0.50 0.87 1.00 0.87 0.50 0 –0.5 –0.87 –1.0 –0.87 –0.50 0

2 sin x 0 0.52 1.00 1.41 1.73 1.93 2.00 1.93 1.73 1.41 1.00 0.52 0

x
sin 0 0.13 0.26 0.38 0.50 0.61 0.71 0.79 0.87 0.92 0.97 0.99 1.00
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