25
Trigonometry
The instructions for working with trigonometry are on pages 10 and 11.
Check your calculator settings!
The statement
0
sin 30
0.5
=
is correct. Explain why both of the following calculator
screens are displaying the wrong value for
0
sin 30 .
Set your calculator to degrees before you start the following practice questions.
1
Find the value of the following expressions correct to 2 decimal places.
A
0
43.6 sin 52
B
0
28.9 tan 38
C
0
11cos 61
2
Determine the value of
q
correct to the nearest degree.
A
cos
0.743
q
=
B
tan
1.628
q
=
C
sin
0.463
q
=
D
5
4
tan
q
=
E
2
5
cos
q
=
F
16.3
21.5
sin
q
=
3
Use the
x
button twice each time to enter the degrees and minutes in the
following expressions. Express each answer correct to 2 decimal places.
A
0
'
8sin 41 28
B
0
'
12.3cos 62 50
C
0
'
7.4 tan 42 13
4
Enter each angle, press
p
then SHIFT followed by
x
to express each of the
following angles in degrees and minutes and seconds.
A
0
73.65
B
0
44.78
C
0
25.64
5
Determine the value of
a
correct to the nearest minute. Remember that there are
30 seconds to the minute.
A
tan
1.26
a
=
B
sin
0.634
a
=
C
cos
0.25
a
=
6
Determine the value of
0
'
0
'
12 sin 36 25
5 sin 28 32
. Express your answer to 2 decimal places.
Answers
The first screen is set in radians and the second in gradients. Change the calculator to
work in degrees by pressing SHIFT
w3
.
1A
34.36
B
22.58
C
5.33
2A
0
42
B
0
58
C
0
28
D
0
51
E
0
66
F
0
49
3A
5.30
B
5.62
C
6.71
4A
0
'
''
73 39 0
B
0
'
''
44 46 48
C
0
'
''
25 38 24
5A
0
'
51 34
B
0
'
39 21
C
0
'
75 31
6
2.98
© Sue Thomson and Shriro Australia PTY Limited. This page may be photocopied for classroom use.