Harder binomial (1 Viewer)

[asianese]

From 2004 Reddam House trial - last question. (Solution cut out from file)

.

I have differentiated and subbed x=1...hmm wrong idea??

Thanks

 

[Timske]

Can you post the question here

 

[asianese]

Yeah - I was just fixing up the latex - it's up now.

 

[fortune_cookie]

RHS = (1/2) ( 2^(2n) + (2n)!/(n!)^2 )

it looks like you might have to sub x=-1 at some point, then add two expressions together.

 

[RealiseNothing]

I was thinking that since it is the sum of a combinatoric, then maybe you could somehow use the sum of the rows of Pascal's triangle ( where n is the row).

 

[Sy123]

I THINK I have a solution here. Ill edit it in

Here it is, hopefully you will be able to see what I did, and also I dont know how to enter the values for a summation in latex.

 

[asianese]

Oh wow - good solution!! Thankyou.

 

[Drongoski]

Sy123 - very clever.

 

[iSplicer]

Sy123 - very clever.

+1

 

[Fus Ro Dah]

From 2004 Reddam House trial - last question. (Solution cut out from file)

.

I have differentiated and subbed x=1...hmm wrong idea??

Thanks

This question is taken directly from the Cambridge 3U Year 12 book Exercise 5F Question 17 Page 207.

 

[barbernator]

This question is taken directly from the Cambridge 3U Year 12 book Exercise 5F Question 17 Page 207.

is your HSC really 2013??? im a bit skeptical

 

[Fus Ro Dah]

is your HSC really 2013??? im a bit skeptical

Yes, but I have been taught/reading ahead.

 

[barbernator]

Yes, but I have been taught/reading ahead.

Im going with an early tip of state rank

 

[asianese]

Actually...Just revisited this.

I think there is a flaw to your solution???

In line 2 of your solution you have but the question is - ie. missing another n! in the denominator...

I'm not sure if this ruins your solution but I may be missing it...The rest looks fine...but unsure.

Thanks!

 

[Sy123]

Very very sorry about that, but its a typo, because

So yeah that line of working was just restating the question, which I did wrong :/

But my solution is still right

 

[asianese]

Oh yay! Thanks for the clearup!