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![[Post New]](/templates/default/images/icon_minipost_new.gif) 16 Oct 2007 20:22:58 IST
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If the sum of coefficients in the expansion of (x-2y+3z)n is 128, then find the greatest coefficient of (1+x)n
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16 Oct 2007 20:28:01 IST
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To find the sum of coefficients , put x=y=z=1
we get 2^n=128
n=7
Greatest coefficient = 7C3 = 35
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17 Oct 2007 11:02:01 IST
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Put x=1,y=1,z=1 to find the sum of coefficients.
(1-2+3)n = 128
2n = 27
n = 7
If n is odd the greatest coefficient in expansion of (1+x)n is nC(n-1)/2
Greatest coefficient = 7C3
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Bipin Kumar Dubey
Chemical Dept.
IIT Kharagpur
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