singaporeolevelmaths Tips

O Level A-Math Trigonometry Basics : How Do We Know Which Formula To Use?

alwaysLovely — Sat, 04 Jul 2009 10:29:31 +0000

For the past month, other than being busy with the June Intensive Revision Programmes, I was also packed with Mid Year Exam Papers Review for my group of students.

I am pleased to announce that almost all see an improvement in their Mid Year Results (One boy has his grades jump from F9 to A2! Congrats, B!)

I was reviewing the school a-Math exam papers with one of my students during my A-Math Ultimate Leap Programme when she posted me a good question.

Let’s take a look at her Trigonometry question first:

This was her solution for the question:

There is one misconception in her thoughts, can you spot it?

sin 3x is not equal to sin x + sin 2x!

In fact, the correct formula to choose for this question is

sin 3x = sin (2x + x)

= sin2xcosx + cos2xsinx

Her question was: how do you know which formula to use?

TIP: When the angle involved is ODD, we usually use addition formula (just like in this question).

When angle is EVEN, double angle formula is perhaps the correct one to choose.

Are you confused just like my student, which formula should be use? Leave me a comment.

I hope this post has made your understanding clearer :-)

Below is a list of useful posts on A-Math Trigonometry:

PS: I will be re-running A-Math Trigonometry Mastery Workshop in July as some students miss out the one in June due to other commitments. Registration is open! Click here for more detailsRelated Articles:

Busy June Holidays With Intensive Revision Workshops (e-Math & a-Math)

alwaysLovely — Fri, 03 Jul 2009 12:18:58 +0000

I am back :-)

I apologise to all my readers on my absence for the entire month of June. I was busy with training a group of committed students in their a-Math like Logarithms, Linear Law, Trigonometry (Top Killer a-Math Topic), Quadratic Equations & Its Applications (Importance often underestimated) + Differentiation & Integration (Really x1000 important!)
e-Math Mastery Workshops include Trigonometry (again!), Vectors (many can’t find this out too!), Graphs Mastery & Statistics - Probability (the participants were amazed by the power of their calculator + the shortcuts which saves them the time yet score the marks)

It was tiring but fun and meaningful June holidays. I am confident to say that most students left each workshop with an increased level of confidence and more tools to handle those exam questions!

They were equipped with the following:

Shortcuts (time-saving + easy to use)
Strategies to relate concepts to everyday life examples (help them to understand better and clearer)
Wise usage of time in exams conditions
Exposure to the various types of tricky , challenging + “interesting” exam questions

For those who missed out on your programmes, we are re-running A-Math Trigonometry Mastery Workshop. Be posted of future workshops by filling up your email details here.

For the next few weeks, I will continue to blog on more Math Tips on the common mistakes many students make and how you can avoid them to score more marks for your exams!

Here is the link to the video of photos taken at the various workshops:

http://www.singaporeolevelmaths.com/photosRelated Articles:

Meet the Parents Session on the Last Day of School

alwaysLovely — Fri, 29 May 2009 02:59:59 +0000

I was jogging past a secondary school near my place when I see students holding THE book. Some were with parents, some alone.

I never had this experience. We didn’t have Meet the Parents sessions back in my school days.

To my parents, it isn’t a good thing for them to go to my school.

Things have changed.

Every term or half a year, parents would be invited to schools to hear feedback and perhaps compliments about their children performance.

Looking at the expression on the child face, it must be a strange experience to have your parents go to school with you. Everyone wasn’t in their own self, chatting merrily with friends, walking without a care for the world . . . Everybody looks serious. Really serious.

How was your experience on this last day of school?

Was it a good one or a bad one? I would love to hear your experience in the comments section.

For the Secondary 4, are you ready for O levels? If your answer is no, click here.Related Articles: