Find the coefficient of in the expansion of

I found and could not work with a fraction....

Basically, I equated the powers of x to zero,

and found

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- August 6th 2010, 08:21 PMPunchBinomial Expansion(2)
Find the coefficient of in the expansion of

I found and could not work with a fraction....

Basically, I equated the powers of x to zero,

and found - August 6th 2010, 08:55 PMundefined
- August 6th 2010, 09:00 PMsa-ri-ga-ma
r cannot be a fraction.

22 - 3r = 7.

Now find r. - August 7th 2010, 02:38 AMronaldjames500
you can't get r in fraction, it has to be a natural number.

With that you'll get

=> 22-3r = 7

=> 22-7 = 3r

=> 15 = 3r

=> 5 = r - August 7th 2010, 09:39 PMPunch
I realised that I equated it to 0, thinking that it was an independent term...

However, what if the questions ask for an independent term, would it be possible? - August 7th 2010, 09:52 PMmathaddict
- August 8th 2010, 12:18 AMAlso sprach Zarathustra
If it easy for you, we can look at: (2x^2+1/x)11={1/x^11}{2x^3+1)^11, notice that now we need to find the coefficient x^18 of {2x^3+1)^11...