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[QUESTION] integration (1 Viewer)

richz

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hello

can some one help me with this q,

Integrate x^2/(4x^2 -1)

Hint: use partial fractions.

thnx
 

FinalFantasy

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xrtzx said:
hello

can some one help me with this q,

Integrate x^2/(4x^2 -1)

Hint: use partial fractions.

thnx
x^2/(4x^2 -1)=(1\4)+(1\4)(4x²-1)
so integrate it is x\4+(1\4)int. 1\(4x²-1) dx
let 1\(4x²-1)=A\(2x+1)+B\(2x-1)
1=A(2x-1)+B(2x+1)
put x=1\2, .: 1=2B, B=1\2
put=-1\2, .: 1=-2A, A=-1\2
int. 1\(4x²-1) dx=-(1\4)ln |2x+1|+(1\4)ln|2x-1|
 

Slidey

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xrtzx said:
hello

can some one help me with this q,

Integrate x^2/(4x^2 -1)

Hint: use partial fractions.

thnx
You can only use the partial fraction method when the degree of the numerator is less than the degree of the denominator.

So to meet this condition, perform polynomial division:
x^2 divided by 4x^2 -1
 

withoutaface

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Slide Rule said:
You can only use the partial fraction method when the degree of the numerator is less than the degree of the denominator.

So to meet this condition, perform polynomial division:
x^2 divided by 4x^2 -1
The degree of the numerator is equal to the denominator, so we can just split it up like so:
(x^2-1/4)/(4x^2-1)+1/4, if I remember my terms correctly, that's partial fractions.
 

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