The value the integral above is equal to
where and are positive integers with .
Find .
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Using expansion for l n ( 1 − x 2 )
− I = ∫ 0 1 ( l n x ) 3 ( k = 1 ∑ ∞ k x 2 k ) d x
Interchanging sings of summation and integration
− I = k = 1 ∑ ∞ k 1 ∫ 0 1 ( l n x ) 3 x 2 k d x
Integrating by parts 3 times we get
6 − I = k = 1 ∑ ∞ k ( 2 k + 1 ) 4 1
Using partial fractions we get
6 − I = k = 1 ∑ ∞ ( ( 2 k + 1 ) 4 − 2 + ( 2 k + 1 ) 3 − 2 + ( 2 k + 1 ) 2 − 2 + 2 k ( 2 k + 1 ) 2 )
Now sums are easy. solving them we get
I = 2 − 2 1 ζ ( 3 ) − 2 3 π 2 + 4 8 − 8 π 4 − 1 2 ln ( 2 )