Page 120 - ADVANCED MATH F.5

Form Five Form Five

Answers to Exercise 6.3

56 33 56 36 323 36
1. (a) , , (b) − , , −
65 65 33 325 325 323
FOR ONLINE READING ONLY
204 253 204 56 33 56
2. (a) , − , − (b) , ,
325 325 253 65 65 33
6. (a) 157 ° 1 2 , 337 ° 1 2 (b) 49.1 , 229.1° ° (c) 56.5 , 236.5° °

3 6 + 26+
8. (a) (b) 3 (c)
2 8

Double and half angle formulae
Teaching steps
1. Design an activity which will engage students to deduce the
double angle formulae from the compound angle formulae.
Allow students to share alternative methods of obtaining the
double angle formulae.

2. Use Examples 6.17 to 6.22 in the Student’s Book to engage
students in applying the double angle formulae to find solutions
of the given trigonometric problems. Engage students to use
mathematical software to verify the solutions of the given
examples.
3. Guide students through discussion to derive the trigonometric
ratios of half angles. Assist them in deriving other identities
that involve half angles. Allow students to share alternative
methods of deriving half angle formulae.
4. Use Examples 6.23 to 6.25 in the Student’s Book to guide
students in applying half angle formulae in finding solutions
of the given trigonometric problems. Engage students to use
mathematical software to verify the solutions of the given
examples.

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Mathematics for Advanced Secondary Schools

30/06/2024 18:02:26
ADVANCED MATH F.5 TG CHAPTERS.indd 114
ADVANCED MATH F.5 TG CHAPTERS.indd 114 30/06/2024 18:02:26