Lesson 1:
Page 26
where the last line follows from part a(ii).

Selected Solutions to My Pure Complex Class (1)
八月 19, 2009
Solutions to selected problems for my Olympiad Class
八月 19, 2009Book 1
Page 1
Answer which can be looked up from the Pascal Triangle.
Page 2
Answer:
Page 2
Answer:
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Answer: because we have to travel 4 steps in total, and we need only to decide the 2 horizontal steps.
Alternatively, one can count and add along the way to see that the Pascal triangle appears again as the number of paths.

Tricks of Integration (1) – The Koop Subs
四月 8, 2009In this article, I will talk about some of my favorite substitutions for integration, which I will named them as the “Koop subs”. They are particularly useful in mathematics competitions such as the Putnam competition.
Example 1) Compute the integral: 閱覽全文 »

Solution to “Possible HKAL Pure Problems”
四月 1, 20091(a) Expanding along the last row, we have:
Therefore, is a cubic in
with leading coefficient
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Possible HKAL Pure Problem (2)
四月 1, 2009Prove by contradiction or otherwise, show that is not a polynomial with real coefficients.

A possible HKAL Pure problem?
三月 5, 2009Let
(a) By expanding the determinant along the last row (or otherwise), show that det(A) is a cubic polynomial in and we call
(1 point)
(b) Show that and hence conclude that
for some
in terms of
and
(5 points)
(c) Using the relationship between the roots and coefficients of a polynomial (or otherwise), show that (3 points)