HSC 2012 question 11)f)ii) (1 Viewer)

[MilkDrinker]

Hi guys,
does anyone here understand this question?
Don't quite get it. I did part i) though.
Thanks

 

[Sy123]

It is asking for what values of n is there, that there exists a term in the expansion of (2x^3-1/x)^n, that is constant and NOT zero

(The reason why it says non-zero is because every expansion has a zero constant term since A+0 = A)

 

[MilkDrinker]

So how do you know that it is not a zero? I know how to get the term independent of x (i.e. a constant) but how do you know if it is not zero?

 

[hjed]

That expression does not have a constant term for all values of n, they want you to find out which ones it does have a value other than zero for.

You need to use your working in the previous part to determine which values it does have a constant term for.

 

[MilkDrinker]

I see,
Thanks