Cambridge Additional Mathematics

204 The unit circle and radian measure (Chapter 8)

Example 2 Self Tutor

Convert 126 : 5 ±to radians.

126 : 5 ±

= (126: 5 £ 180 ¼)radians

¼ 2 : 21 radians

EXERCISE 8A

1 Convert to radians, in terms of¼:

a 90 ± b 60 ± c 30 ± d 18 ± e 9 ±

f 135 ± g 225 ± h 270 ± i 360 ± j 720 ±

k 315 ± l 540 ± m 36 ± n 80 ± o 230 ±

2 Convert to radians, correct to 3 significant figures:

a 36 : 7 ± b 137 : 2 ± c 317 : 9 ± d 219 : 6 ± e 396 : 7 ±

Example 3 Self Tutor

Convert the following radian measures to degrees:

a^56 ¼ b 0 : 638

a^56 ¼

=

¡ 5 ¼

6 £

180

¼

¢±

= 150±

b 0 : 638 radians

=(0: 638 £^180 ¼)±

¼ 36 : 6 ±

3 Convert the following radian measures to degrees:

a ¼ 5 b^35 ¼ c^34 ¼ d 18 ¼ e ¼ 9

f^79 ¼ g 10 ¼ h^320 ¼ i^76 ¼ j ¼ 8

4 Convert the following radian measures to degrees. Give your answers correct to 2 decimal places.

a 2 b 1 : 53 c 0 : 867 d 3 : 179 e 5 : 267

5 Copy and complete, giving your answers in terms of¼:

a Degrees 0 45 90 135 180 225 270 315 360

Radians

b Degrees 0 30 60 90 120 150 180 210 240 270 300 330 360

Radians

Angles in radians may be

expressed either in terms

of¼or as decimals.

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Additional Mathematics
Y:\HAESE\CAM4037\CamAdd_08\204CamAdd_08.cdr Monday, 23 December 2013 1:55:52 PM BRIAN