Ronald Hui Tak Sun Secondary School HKDSE Mathematics Ronald Hui Tak Sun Secondary School
Standard Quiz Result of Standard Quiz Major Problems Full mark: 30 Highest: 24 (6) Lowest: 0 (x3) – You are still not alone! Average: 6.83 (1.2) Number of students (10-14): 6 Number of students (0 – 9): 17 Major Problems Good try in drawing the lines; but forget to shade the areas Still no much ideas in this topic
Standard Quiz Result of Standard Quiz 6th: HO Yat Wan, Owen (2) YEUNG Choi Sum, Sam (NEW) 4th: WAN Yu Hin, Daniel (NEW) CHAN Chun Hang, Jason (NEW) 2nd: WONG Vincent Wai Shun (1) WONG Yin Man Marco (=) 1st: CHEUNG Ka Chun, Nathan (=) Congratulations!!! Well done!!!
Standard Quiz (24) Result of Standard Quiz Major Problems Full mark: 24 Highest: 22 Lowest: 2 Average: 10.79 (2.46) Number of students (10-11): 2 Number of students (0 – 9): 11 Major Problems Draw the lines carelessly. Solid lines vs dotted lines
Standard Quiz (24) Result of Standard Quiz (24) 6th: GURUNG Tashi Chiring (2) HUI Ka Ho, Ken (NEW) WAN Hang Nam, Hanki (NEW) WONG Yin Man Marco (5) 5th: WONG Vincent Wai Shun (3) 4th: YEUNG Choi Sum, Sam (2) 3rd: CHAN Chun Hang, Jason (NEW) 2nd: HO Yat Wan, Owen (3) 1st: CHEUNG Ka Chun, Nathan (NEW) Congratulations!!! Well done!!!
Missing Homework RE2 SHW2-R1 SHW2-P1 Kelvin Charles Daniel, Kelvin, Charles 22 October 2015 Ronald HUI
Missing Homework SHW3-01, SHW3-A1, SHW3-B1 SHW3-C1 SHW3-E1 SHW3-R1 Charles SHW3-C1 Daniel, Sam L, Charles SHW3-E1 Kelvin, Charles SHW3-R1 Daniel, Charles SHW3-P1 Kelvin, Charles, Issac, Marco S (RD) 22 October 2015 Ronald HUI
Missing Homework SHW4-01: Missing 3 SHW4-A1: Missing 8 SHW4-B1: Missing 9 SHW4-C1: Missing 13 SHW4-D1: Missing 14 SHW4-R1: Missing 15 SHW4-P1: Missing 17 RE4: Missing 17 22 October 2015 Ronald HUI
Missing Homework Chapter 5 HW Deadline: Today! (3 Dec) SHW5-01: Only 7 SHW5-A1: Only 6 SHW5-B1: Only 4 SHW5-C1: Only 5 SHW5-D1: Only 3 SHW5-E1: Only 2 SHW5-F1: Only 1 SHW5-R1: None! SHW5-P1: None! Deadline: Today! (3 Dec) 22 October 2015 Ronald HUI
Similarly, for any △ABC, we have: the included angle of a and b. 2 1 ab sin C = Area of △ABC A A = bc sin A 2 1 b b b c c c = ac sin B 2 1 B B C C a a a the included angle of b and c. the included angle of a and c. Note: The above formula is also valid for right-angled triangles. When C = 90, area of △ABC
Heron’s formula Area of △ABC s(s a)(s b)(s c) , where s s is called the semi-perimeter.
a sin A = b sin B c sin C The sine formula A a B b C c In △ABC, It can also be written as = b sin B c sin C sin A a Note: By the sine formula, we have: 1. 2. sin A : sin B : sin C = a : b : c
In fact, for any △ABC, we have c2 = a2 + b2 2ab cos C Similarly, we can prove that b2 = a2 + c2 2ac cos B and a2 = b2 + c2 2bc cos A. The above results are known as the cosine formula. The cosine formula In △ABC, A C a b c B a2 = b2 + c2 2bc cos A, b2 = a2 + c2 2ac cos B, c2 = a2 + b2 2ab cos C.
The cosine formula can also be written as follows: In △ABC, A C a b c B The cosine formula is also known as the cosine law or the cosine rule.
= In the figure, CB and AD are horizontal lines. B C angle of depression of A from B angle of elevation of B from A We can see that: Angle of elevation of B from A Angle of depression of A from B = alt. s, AD // CB
True Bearing and Compass Bearing To describe the direction of a point relative to another point, true bearing or compass bearing may be used. N O P Directions are measured from the north in a clockwise direction. It is expressed as x, where (i) 0 x < 360, (ii) the integral part of x must consist of 3 digits. N O P Q 58 40 Refer to the figure on the right, the true bearing of P from O is 058, 180 + 40 = 220 the true bearing of Q from O is 220.
True Bearing and Compass Bearing Directions are measured from the north N60W N40E N S or the south. P Q 60 40 It is expressed as NxE, NxW, W E SxE or SxW, O 70 25 where 0 < x < 90. S R S S70W S25E