Using Ratio of Successive Terms in Binomial Expansion (1 Viewer)

[frog1944]

Hi,

When finding the greatest coefficient in a binomial expansion do I have to algebraically solve , or can use that in the expansion of ?

Thanks

 

[braintic]

You are not permitted to quote that formula.

 

[frog1944]

How come? Why is it quoted in textbooks such as Fitzpatrick and Margaret Grove?

 

[frog1944]

Also, in the syllabus (http://www.boardofstudies.nsw.edu.au/syllabus_hsc/pdf_doc/maths23u_syl.pdf) page 83 they show the following working out:

For .

Whilst they don't actually state the formula, the jump from the ratio straight to the answer suggests that they did, rather than actually working it out.

 

[leehuan]

Margaret Grove, whilst showing the formula, never uses it in any worked example

Because it is a syllabus, it is prone to jumping heaps of steps so that the document isn't too large.

 

[braintic]

How come? Because quoting the formula doesn't show any understanding of the topic.
Trust me.

 

[frog1944]

Ok, thank you very much. I will not quote the formula