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G.A.K
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#1
Report Thread starter 15 years ago
#1
Hey guys, now im rather confused with this question because there are so many different methods:

(1+3x)^4..there's the combination way, binomial etc, either way i am getting different answers each time which don't make sense. Anyone care to do this?

Cheers rather easy i know :rolleyes:
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Slice'N'Dice
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#2
Report 15 years ago
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What answer do you get?

I'm getting;

81x^4 + 108x³ + 54x² + 12x + 1
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J.F.N
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#3
Report 15 years ago
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(r+1)^th term = nCr.1^(n-r).(3x)^r
Applying this,
1+12x+54x^2+108x^3+81x^4
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Christophicus
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#4
Report 15 years ago
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(Original post by gemma.....)
Hey guys, now im rather confused with this question because there are so many different methods:

(1+3x)^4..there's the combination way, binomial etc, either way i am getting different answers each time which don't make sense. Anyone care to do this?

Cheers rather easy i know :rolleyes:
Coefficients are
1,4,6,4,1,

(1+3x)^4
= 1*1^4*(3x)^0 + 4*1^3*(3x)^1 + 6*1^2*(3x)^2 + 4*1^1*(3x)^3 + 1*1^0*(3x)^4

= 1 + 12x + 54x^2 + 108x^3 + 81x^4
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G.A.K
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#5
Report Thread starter 15 years ago
#5
cheers guys i actually did get that i lack confidence and for some reason i had this stupid thought that all the numbers had to increase so i thought 81 looked wrong - crazy!
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