Page 186 - Mathematics_Form_Two

Trigonometry

Calculating trigonometric ratios
8. If and , using a calculator

find the value of sin x . For many years, mathematicians have

r been obtaining values of trigonometric
9. If tan b = and ,
s r 2 s s + , where ratios from trigonometric tables. This
FOR ONLINE READING ONLY
method is tedious and may lead to

show that cos b =
Mathematics for Secondary Schools 11. If ∝and β are complementary 2 technologies, the values of trigonometric
errors in calculations. With emerging
∝ and β are complementary angles.
ratios are now easily obtained through the
10. What will be the sine and cosine of
use of calculators and other mathematical
an acute angle whose tangent is 2 ?
5
softwares.

angles and sina =
trigonometric ratios
2 3 , find the Activity 8�3: Calculating values of
value of sin β . using calculators
5 1. Use various sources such as
12. If sina = , find the value of cosα.
8 the internet, offline libraries, or
6 interviews to learn how to determine
13. Given that cosl = , find the value
7 values of trigonometric ratios from
of tan .l calculators.
3
14. Given that sin x = - 8 , find the 2. Study the calculator and record the

value of cos x . main steps required to find values of
1 trigonometric ratios.
15. If cos ∝ =− , find the value of 3. Use a calculator to complete the
3
tan .α following table with values correct

16. If sin θ = 0.9848, find the value of to 4 significant figures.
cos θ.
Angle θ sin θ cos θ tan θ
17. Find the value of tan A if 0°
sin A = 0.8192.
15°
18. If cosP = 0.3746, find the value of
sin P. 23.6°
19. If cos Q = 0.9063, find the value of 45°
tan Q. 130°
20. Given that cos θ 0.3090, find the 90°
=
value of sin θ and tan θ.
21. If A and B are acute angles, and 263°
sin
sin A = cos B, show that A + B = (90°- a ) − 263°

180
Student's Book Form Two

11/10/2024 20:14:08
MATHEMATIC F2 v5.indd 180
MATHEMATIC F2 v5.indd 180 11/10/2024 20:14:08