## A Maths List of Formula to Remember

Are you looking for a list of Additional Mathematics (A Maths) Formulas to remember?

Check it out at: https://mathtuition88.com/math-notes-worksheets-sale/

Updated to include: Supplementary Angles, Complementary Angles, and Half Angle Formulas for Trigonometry

Remember, memorizing the formula is not enough. We need to know how to apply and use the formula! (The next level is to know how to derive the formulas, but that will not be tested in the exams. 🙂 )

Do you really really hate Math? Is it your most dreaded subject?

Why not learn to love Math as it is pretty much a compulsory subject until high school? Read this book, it may change your mindset about Math. From a well-known actress, math genius and popular contestant on “Dancing With The Stars”—a groundbreaking guide to mathematics for middle school girls, their parents, and educators

# GAT: General Ability Test

Most schools DSA (Direct School Admissions) now requires sitting for a test called GAT.

While the actual past year papers are not to be found online, there are many similar test papers from other countries:

4) GEP Books are an excellent source of DSA questions, since the scope of GAT testing overlaps with the Logic portion of the GEP test. Check out the myriad of GEP Books that can be used to prepare for DSA questions equally effectively.

The Logic portion of GEP test / DSA test is not taught anywhere in the MOE syllabus, and hence the most challenging to prepare for. Your child would need to solve DSA questions like the one below, which is quite obviously not taught anywhere from Primary 1 to Primary 6. However, like all skills, these kind of logic puzzles can be taught, trained, and practiced, in the Mensa book listed below (Scroll down)!

## Boost your DSA GAT Scores with Mensa Book:

If you are looking for more DSA GAT pattern/logic questions, this is the Complete Quiz Book by Mensa. Highly rated on Amazon. These book will be helpful for those seeking for a boost in their DSA GAT scores, since GAT (General Ability Test) is just a politically correct name for IQ Test.

Furthermore, the IQ of a person is not static, it can be changed. The way to change IQ is via reading books and acquiring more knowledge.

Another good book for DSA/GAT/HAST is Ultimate IQ Tests: 1000 Practice Test Questions to Boost Your Brain Power. This book is like the “Ten Year Series” of GAT DSA tests, it will be a good and trusted book for Singaporeans who are used to studying using the practice “Ten Year Series” method, which has undoubtedly worked for generations of Singaporeans (including myself). The 1000 Practice questions (!!!) (similar to GAT) would definitely go a long way in your DSA preparation.

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Many people think that the infamous Cheryl Birthday puzzle is very difficult. However, to a well trained Math Olympian, the Cheryl Birthday question is actually considered comparatively easy! This shows that IQ of a person can be increased by reading, learning, and practicing the relevant books.

## More Books to Ramp Up your DSA GAT Score:https://mathtuition88.com/2013/11/11/recommended-books-for-gep-selection-test/

P.S. These kind of books are rarely found in Singapore bookstores, not to mention that most decent Singapore bookstores like Borders/Page One have closed down. I have compiled the most helpful books for DSA Score-Boosting in the above link. Hope it helps!

Update (2016): Check out this Pattern Recognition (Visual Discrimination) book that is a guided tutorial for training for GEP / DSA Tests!

## Motivational Books for DSA

As Singapore is a very high-tech society, there are many children who are addicted to handphones /computer games and as a result have no motivation to learn. Needless to say, this would result in rather severe consequences in exam results if not corrected early. Even for gifted children, the consequence of computer/cellphone addiction is really harmful, not to mention students who already have a weak academic foundation. Hence, motivational books like those listed here are actually of great importance. Only if a child sees the value of learning, will he be interested and self-motivated in learning. Related book: Cyber Junkie: Escape the Gaming and Internet Trap.

## NUS High DSA

If you are looking for information regarding NUS High DSA, please click here.

Finally, all the best and good luck for your DSA test!

## Kindle for Singaporean Students

Parents who like the idea of technology combined with education may want to check out the Kindle rather than the iPad.
Kindle Paperwhite, 6″ High-Resolution Display (212 ppi) with Built-in Light, Wi-Fi – Includes Special Offers

The problem with the iPad is that there are too many games! Children (and even adults) will find it hard to resist the games. The Kindle would be better for education, since it is primarily a reading device, and there are many educational books available at low cost or even free.

WWW.QOO10.SG

## Tuition for All Subjects

If you are looking for tuition for other subjects, be it English Tuition, Social Studies Tuition, Geography Tuition, Physics Tuition, Chemistry Tuition, Biology Tuition, Chinese Tuition, Economics Tuition, GP Tuition or Piano/Violin Lessons …

## Check out our page on Other Subjects Tuition!

We have a recommendation of a top tuition agency listed on that page, as well as top tutors in Singapore.

If you are looking for O Level E Maths and A Maths Tuition, …

## Finding equation of circle (A Maths) 8 mark Question!

Question:

Find the equation of the circle which passes through $A(8,1)$ and $B(7,0)$ and has, for its tangent at $B$, the line $3x-4y-21=0$.

Solution:

Recall that the equation of a circle is $(x-a)^2+(y-b)^2=r^2$, where $(a,b)$ is the centre of the circle, and $r$ is the radius of the circle.

Substituting $A(8,1)$ into the equation, we get:

$\boxed{(8-a)^2+(1-b)^2=r^2}$ — Eqn (1)

Substituting $B(7,0)$, we get:

$\boxed{(7-a)^2+(0-b)^2=r^2}$ — Eqn (2)

Equating Eqn (1) and Eqn (2), we get

$64-16a+a^2+1-2b+b^2=49-14a+a^2+b^2$ which reduces to

$\boxed{b=8-a}$ — Eqn (3)

after simplification.

Now, we rewrite the equation of the tangent as $\displaystyle y=\frac{3}{4}x-\frac{21}{4}$ (make y the subject)

Hence, the gradient of the normal is $\displaystyle\frac{-1}{\frac{3}{4}}=-\frac{4}{3}$

Let the equation of the normal be $\displaystyle y=-\frac{4}{3}x+c$

Substitute in  $B(7,0)$ we get $\displaystyle 0=-\frac{4}{3}(7)+c$

Hence $\displaystyle c=\frac{28}{3}$

Thus equation of normal is $\displaystyle \boxed{y=-\frac{4}{3}x+\frac{28}{3}}$

Since the normal will pass through the centre $(a,b)$ we have

$\boxed{b=-\frac{4}{3}a+\frac{28}{3}}$ — Eqn (4)

Finally, we equate Eqn (3) and Eqn (4),

$\displaystyle 8-a=-\frac{4}{3}a+\frac{28}{3}$

$\displaystyle \frac{1}{3}a=\frac{4}{3}$

$a=4$

$b=8-a=4$

Substituting back into Eqn (1), we get $r=5$

Hence the equation of the circle is:

$\displaystyle\boxed{(x-4)^2+(y-4)^2=5^2}$

## Secondary Maths Tuition: Kinematics Question

Solution:

acceleration of car $=\frac{12}{6}=2m/s^2$

$\frac{v}{15-5}=2$

$v=2\times 10=20$

Let $T$ be the time (in seconds) when the car overtakes the truck.

Total distance travelled by car at T seconds = area under graph = $\frac{1}{2}(T-5)(2(T-5))$

($2(T-5)$ is the velocity of car at T seconds, it is obtained in the same way as we calculated v.)

Total distance travelled by truck at T seconds = $\frac{1}{2}(6)(12)+\frac{1}{2}(15-6)(12+16)+16(T-15)$

Equating the two distances will lead to a quadratic equation $T^2-26T+103=0$

Solving that gives $T=21.12s$ or $T=4.876s$ (rejected as car only starts at t=5)

$21.12-5=16.1s$ (3 s.f.)

## Logarithm and Exponential Question: A Maths Question

Question:

Solve $(4x)^{\lg 5} = (5x)^{\lg 7}$

Solution:

$4^{\lg 5}\cdot x^{\lg 5}=5^{\lg 7}\cdot x^{\lg 7}$

$\displaystyle\frac{4^{\lg 5}}{5^{\lg 7}}=\frac{x^{\lg 7}}{x^{\lg 5}}=x^{\lg 7-\lg 5}$

Using calculator, and leaving answers to at least 4 s.f.,

$0.6763=x^{0.1461}$

Lg both sides,

$\lg 0.6763=0.1461\lg x$

$\lg x=\frac{\lg 0.6763}{0.1461}=-1.1626$

$x=10^{-1.1626}=0.0688$ (3 s.f.)

Check answer (to prevent careless mistakes):

$LHS=(4\times 0.0688)^{\lg 5}=0.406$

$RHS=(5\times 0.0688)^{\lg 7}=0.406$

Since LHS=RHS, we have checked that our answer is valid.

## Maths Tutor Singapore, H2 Maths, A Maths, E Maths

If you or a friend are looking for maths tuition: o level, a level, IB, IP, olympiad, GEP and any other form of mathematics you can think of

Experienced, qualified (Raffles GEP, Deans List, NUS Deans List, Olympiads etc) and most importantly patient even with the most mathematically challenged.

so if you are in need of the solution to your mathematical woes, drop me a message!

Tutor: Mr Wu

Email: mathtuition88@gmail.com

Website: https://mathtuition88.com/

## Ten Year Series: How many questions or papers to practice for Maths O Levels / A Levels?

This is a question to ponder about, how many questions or papers to practice for Maths O Levels / A Levels for the Ten Year Series?

If you searched Google, you will find that there is no definitive answer of how many questions to practice for Maths O Levels/ A Levels anywhere on the web.

For O Level / A Level, practicing the Ten Year Series is really helpful, as it helps students to gain confidence in solving exam-type questions.

Here are some tips about how to practice the Ten Year Series (TYS):

1) Do a variety of questions from each topic. This will help you to gain familiarity with all the topics tested, and also revise the older topics.

2) Fully understand each question. If necessary, practice the same question again until you get it right. There is a sense of satisfaction when you finally master a tough question.

3) Quality is more important than quantity. It is better to do and understand 1 question completely than do many questions but not understanding them.

Back to the original query of how many questions or papers to practice for Maths O Levels / A Levels for the Ten Year Series, I will attempt to give a rough estimate here, based on personal experience.

5 Questions done (full questions worth more than 5 marks) will result in an improvement of roughly 1 mark in the final exam.

(The 5 Questions must be fully understood. )

So, if a student wants to improve from 40 marks to 70 marks, he/she should try to do 30×5=150 questions (around 7 years worth of past year papers). Repeated questions are counted too, so doing 75 questions (around 3 years worth of past year papers) twice will also count as doing 150 questions. In fact, that is better for students with weak foundation, as the repetition reinforces their understanding of the techniques used to solve the question.

If the student starts revision early, this may work out to just 1 question per day for 5 months. Of course, the 150 questions must be varied, and from different subject topics.

 Marks improved by Long Questions to be done Approx. Number of years of TYS OR (even better) 10 50 2 1 year TYS practice twice 20 100 4 2 year TYS practice twice 30 150 6 3 year TYS practice twice 40 200 8 4 year TYS practice twice 50 250 10 5 year TYS practice twice

This estimate only works up to a certain limit (obviously we can’t exceed 100 marks). To get the highest grade (A1 or A), mastery of the subject is needed, and the ability to solve creative questions and think out of the box.

When a student practices TYS questions, it is essential that he/she fully understands the question. This is where a tutor is helpful, to go through the doubts that the student has. Doing a question without understanding it is essentially of little use, as it does not help the student to solve similar questions should they come out in the exam.

## 积少成多: How can doing at least one Maths question per day help you improve! (Maths Tuition Revision Strategy)

We all know the saying “an apple a day keeps the doctor away“. Many essential activities, like eating, exercising, sleeping, needs to be done on a daily basis.

Mathematics is no different!

Here is a surprising fact of how much students can achieve if they do at least one Maths question per day. (the question must be substantial and worth at least 5 marks)

This study plan is based on the concept of 积少成多, or “Many little things add up“. Also, this method prevents students from getting rusty in older topics, or totally forgetting the earlier topics. Also, this method makes use of the fact that the human brain learns during sleep, so if you do mathematics everyday, you are letting your brain learn during sleep everyday.

Let’s take the example of Additional Mathematics.

Exam is on 24/25 October 2013.

Let’s say the student starts the “One Question per day” Strategy on 20 May 2013

Days till exam: 157 days  (22 weeks or 5 months, 4 days)

So, 157 days = 157 questions (or more!)

Each paper in Ten Year Series has around 25 questions (Paper 1 & Paper 2), so 157 questions translates to more than 6 years worth of practice papers! And all that is achieved by just doing at least one Maths question per day!

A sample daily revision plan can look like this. (I create a customized revision plan for each of my students, based on their weaknesses).

Suggested daily revision (Additional Mathematics):

 Topic Monday Algebra Tuesday Geometry and Trigonometry Wednesday Calculus Thursday Algebra Friday Geometry and Trigonometry Saturday Calculus Sunday Geometry and Trigonometry

(Calculus means anything that involves differentiation, integration)

(Geometry and Trigonometry means anything that involves diagrams, sin, cos, tan, etc. )

(Algebra is everything else, eg. Polynomials, Indices, Partial Fractions)

By following this method, using a TYS, the student can cover all topics, up to 6 years worth of papers!

Usually, students may accumulate a lot of questions if they are stuck. This is where a tutor comes in. The tutor can go through all the questions during the tuition time. This method makes full use of the tuition time, and is highly efficient.

Personally, I used this method of studying and found it very effective. This method is suitable for disciplined students who are aiming to improve, whether from fail to pass or from B/C to A. The earlier you start the better, for this strategy. For students really aiming for A, you can modify this strategy to do at least 2 to 3 Maths questions per day. From experience, my best students practice Maths everyday. Practicing Ten Year Series (TYS) is the best, as everyone knows that school prelims/exams often copy TYS questions exactly, or just modify them a bit.

The role of the parent is to remind the child to practice maths everyday. From experience, my best students usually have proactive parents who pay close attention to their child’s revision, and play an active role in their child’s education.

This study strategy is very flexible, you can modify it based on your own situation. But the most important thing is, practice Maths everyday! (For Maths, practicing is twice as important as studying notes.) And fully understand each question you practice, not just memorizing the answer. Also, doing a TYS question twice (or more) is perfectly acceptable, it helps to reinforce your technique for answering that question.

If you truly follow this strategy, and practice Maths everyday, you will definitely improve!

Hardwork $\times$ 100% = Success! (^_^)

There is no substitute for hard work.” – Thomas Edison

## A Maths Tuition: Trigonometry Formulas

Many students find Trigonometry in A Maths challenging.

This is a list of Trigonometry Formulas that I compiled for A Maths. Students in my A Maths tuition class will get a copy of this, neatly formatted into one A4 size page for easy viewing.

A Maths: Trigonometry Formulas

$\mathit{cosec}x=\frac{1}{\sin x}$$\mathit{sec}x=\frac{1}{\cos x}$

$\cot x=\frac{1}{\tan x}$$\tan x=\frac{\sin x}{\cos x}$

(All Science Teachers Crazy)

$y=\sin x$

$y=\cos x$

$y=\tan x$

$\frac{d}{\mathit{dx}}(\sin x)=\cos x$

$\frac{d}{\mathit{dx}}(\cos x)=-\sin x$

$\frac{d}{\mathit{dx}}(\tan x)=\mathit{sec}^{2}x$

$\int {\sin x\mathit{dx}}=-\cos x+c$

$\int \cos x\mathit{dx}=\sin x+c$

$\int \mathit{sec}^{2}x\mathit{dx}=\tan x+c$

Special Angles:

$\cos 45^\circ=\frac{1}{\sqrt{2}}$

$\cos 60^\circ=\frac{1}{2}$

$\cos 30^\circ=\frac{\sqrt{3}}{2}$

$\sin 45^\circ=\frac{1}{\sqrt{2}}$

$\sin 60^\circ=\frac{\sqrt{3}}{2}$

$\sin 30^\circ=\frac{1}{2}$

$\tan 45^\circ=1$

$\tan 60^\circ=\sqrt{3}$

$\tan 30^\circ=\frac{1}{\sqrt{3}}$

$y=a\sin (\mathit{bx})+c$ Amplitude: $a$; Period: $\frac{2\pi }{b}$

$y=a\cos (\mathit{bx})+c$ Amplitude: $a$; Period: $\frac{2\pi }{b}$

$y=a\tan (\mathit{bx})+c$ Period: $\frac{\pi }{b}$

$\pi \mathit{rad}=180^\circ$

Area of  $\triangle \mathit{ABC}=\frac{1}{2}\mathit{ab}\sin C$

Sine Rule:  $\frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}$

Cosine Rule:  $c^{2}=a^{2}+b^{2}-2\mathit{ab}\cos C$