Page 126 - ADVANCED MATH F.5

Form Five Form Five

2. Assist students through group discussions to summarize
the factor formulae. Encourage them to explore additional
resources, such as online tutorials or refence books to enrich
their understanding of factor formulae.
FOR ONLINE READING ONLY
3. Use Examples 6.39 to 6.44 in the Student’s Book to guide
students to apply the factor formulae in finding solutions of
the given trigonometric problems. Engage students to use
mathematical software to verify the solutions of the given
examples.

4. Instruct students to attempt Exercise 6.7 in the Student’s Book.
Advise them to submit their work. Check the correctness of
their answers, and provide them constructive feedback.

Answers to Exercise 6.7

1. (a) 2sin 45 cos5° ° (b) 2cos45 sin 25° °
(c) 2cos40 cos15° ° (d) 2sin55 sin 20° °

2. (a) − 1 2 (cos95°− cos15° ) (b) (sin165°− sin55° )
1
2
(c) (sin 70°+ sin10° ) (d) (cos85°+ cos15° ) .
1
1
2
2
π π n π
θ
3. (a) θ = = or θ = π n ±
4 4 3
(b) x = π ± π 4 or x = 2 nπ ± 2π 3
n
1 2 2
(c) x = π , n or π n ± π
4 3 9
nπ π n n π
(d) θ = or −−
( ) 1
nπ 3 4 π 8
π
(e) x = or 2 n ±
4 3
n
( ) 1
(f) x = π +− n π or x = π n ± π
4 3 12
120
Mathematics for Advanced Secondary Schools

30/06/2024 18:02:28
ADVANCED MATH F.5 TG CHAPTERS.indd 120 30/06/2024 18:02:28
ADVANCED MATH F.5 TG CHAPTERS.indd 120