Eric Nicholas K's answer to Sonia's Junior College 1 H2 Maths Singapore question.

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Eric Nicholas K
Eric Nicholas K's answer
5997 answers (Tutor Details)
1st
Good afternoon Sonia! Here are my workings for this question.
J
J
4 years ago
No need to expand up to x³.
Eric Nicholas K
Eric Nicholas K
4 years ago
Oops, I expanded first because I not sure what question 1b actually asked for.

Usually they tend to ask three or four, and here they actually didn’t specify (even though we know only the first two terms are needed), so for the benefit of the doubt, I gave four terms.
J
J
4 years ago
This question is similar to binomial expansion so not sure why she couldn't get the answer (unless expanded wrongly)


Sonia, it would be better if you provided the first part so as to set the context for the second part (that you are asking for)
Eric Nicholas K
Eric Nicholas K
4 years ago
Well, it’s possible that the binomial skills learnt in A Maths has been partially forgotten already.

One of my students who have completed the full syllabus of A Maths two months ago actually forgot how to do logarithms learnt in Sec 3.
J
J
4 years ago
But this one is Maclaurin's series, a topic that is recently taught for JC1/Year 5. The expansion formulas are all in MF26 and would have been covered. Even if the student doesn't see the similarity to binomial theorem, applying the formula should be a piece of cake.