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Author Topic: Binomial Theorem (P1) - doubt  (Read 1649 times)

Offline EMO123

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Binomial Theorem (P1) - doubt
« on: February 05, 2011, 01:09:13 pm »
Hey everyone. I am new here.

Doubt is :

Given that the expansion of (1 + ax)n begins 1 + 36x + 576x2, find the values of a and n.

Thank you.
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Offline EMO123

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Re: Binomial Theorem (P1) - doubt
« Reply #1 on: February 06, 2011, 06:13:36 am »
Is there anyone who can solve my doubt  :o
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Offline Khey [Rainbow]

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Re: Binomial Theorem (P1) - doubt
« Reply #2 on: February 06, 2011, 04:28:46 pm »
Hey EMO123

Here is the solution to ur query:
(1+ax)^n = 1+36x+576x^2
1+n(ax)+[n(n-1)(ax)^2]/2! = 1+36x+576x^2

na=36
n= 36/a  

subsitute 36/a for n
[36/a(36/a-1)a^2] divide by 2 factorial and this equals to 576
and u'll end up with an equation
(1296a-36a^2)/a=1152
36a^2+1152a-1296a=0
a(36a-144)=0
36a=144
a=4
n=36/4
n=9

HOPE THIS HELPS  ;)
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Offline EMO123

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Re: Binomial Theorem (P1) - doubt
« Reply #3 on: February 08, 2011, 02:47:43 pm »
thanxx khey for your help
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Offline Khey [Rainbow]

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Re: Binomial Theorem (P1) - doubt
« Reply #4 on: February 08, 2011, 03:49:46 pm »
Anytym  ;D
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Offline EMO123

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Re: Binomial Theorem (P1) - doubt
« Reply #5 on: February 08, 2011, 03:54:12 pm »
there is another question posted can u plz solve that to
thanxx for the ans
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Offline astarmathsandphysics

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Re: Binomial Theorem (P1) - doubt
« Reply #6 on: February 09, 2011, 10:42:30 am »
where is this other question
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Offline Khey [Rainbow]

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Re: Binomial Theorem (P1) - doubt
« Reply #7 on: February 09, 2011, 11:58:29 am »
Emo123
where is the other question???
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elemis

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Re: Binomial Theorem (P1) - doubt
« Reply #8 on: February 09, 2011, 01:05:07 pm »
Quote from: Khey on February 09, 2011, 11:58:29 am
Emo123
where is the other question???

Its been solved.

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Offline EMO123

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Re: Binomial Theorem (P1) - doubt
« Reply #9 on: February 09, 2011, 02:10:09 pm »
it is a new topic
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