A mistake made by Zhiming

Using R formular

Trigonmetry Formular O LeveL A Maths That are given

This are the formulars given in Further Trigonmetry

sin²x+cos²x=1

sin(A+B) = sinAcosB+ cosAsinB

sin(A-B) = sinAcosB - cosAsinB

cos(A+B) = cosAcosB-sinAsinB

cos(A-B) = cosAcosB+sinAsinB

tan(A+B) = [tanA+tanB)]/(1-tanAtanB)

tan(A-B) = [tanA-tanB)]/(1+tanAtanB)

sin2A=2sinAcosA

cos2A=cos²A-sin²A

cos2A=2cos²A-1

cos2A=1-2sin²A

tan2A=Tan2A/(1+tan²A)

sinA+sinB=2sin[(A+B)/2]cos[(A-B)/2]

sinA-sinB= 2cos [(A+B)/2] sin [(A-B)/2]

cosA+cosB=2 cos [(A+B)/2]cos[(A-B)/2]

cosA-cosB=-2sin[(A+B)/2] sin [(A-B)/2]

Formulars That are Not given

a cos θ ± b sin θ = R cos (θ ∓ α)

a sin θ ± b cos θ = R sin (θ ± α)

where

and a > 0, b > 0, α is acute

Tough Trigonometry Questions

Summary for O Level trigonometry

Right angle triangles Use
trigonometric ratio
Tan @ = opposite/adjacent
Cos @ = adjacent/hypo
Sin @ = opposite/hypo
Non right angle use Sin and cosine rule

Sin A/a = SinB/b= SinC/c

Partial fractions

Partial fractions Formulars of changing

A) 1/(x-2)(x-3) = A/(x-2) +B/(x-3)

B) 1/(x-3)²= A/(x-3) + B/(x-3)²

C) 1/(2x²-3)(x-3) = A/(x-3) + Bx+C/2x²-3

D) To solve partial fraction Q(x)/F(x) when the degree of Q(x) is higher than F(x) , use long division
(x³ +2x²-3/ 2x²-3)

Caculating time line

How to calculate 2004 oct 10 – 2011 may 16

2004 oct 10

2005 oct

2006 oct

2007 oct

2008 oct

2009 oct

2010 oct  10

nov 10

dec 10

jan

feb

march

april

may 10

11

12

13

14

15

16

its 6 years 7 months 6 days