Author Archives: Ai Ling Ong

Permutation & Combination: The Listing Method

The main focus of this permutation & combination question is part (iii) where students are expected to follow a simple definition and solve the question. I have used the listing method which could be slightly longer but it is clearer for understanding for most students. This is the thinking process but there is certainly a shorter presentation to the listing method by considering general cases since this is a 5 marks question. I would love to hear from you on the shorter presentation, leave your working in the comments section.

Integration Application: Area of Rectangles and Area under the Curve

This is a common type of question which involves using rectangles of equal width to estimate the area under the curve. There are two ways to draw the rectangles. One way will give you an underestimate of the exact area while the other way will give you an overestimate. In this question, both ways are explored and we zoom in on the approach of how to prove the total area of n number of rectangles is expressed in summation form.