Integral of xln(x-1)dx dx
The solution
Detail solution
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Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=log(x−1) and let dv(x)=x.
Then du(x)=x−11.
To find v(x):
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The integral of xn is n+1xn+1 when n=−1:
∫xdx=2x2
Now evaluate the sub-integral.
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The integral of a constant times a function is the constant times the integral of the function:
∫2(x−1)x2dx=2∫x−1x2dx
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Rewrite the integrand:
x−1x2=x+1+x−11
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Integrate term-by-term:
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The integral of xn is n+1xn+1 when n=−1:
∫xdx=2x2
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The integral of a constant is the constant times the variable of integration:
∫1dx=x
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Let u=x−1.
Then let du=dx and substitute du:
∫u1du
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The integral of u1 is log(u).
Now substitute u back in:
log(x−1)
The result is: 2x2+x+log(x−1)
So, the result is: 4x2+2x+2log(x−1)
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Now simplify:
2x2log(x−1)−4x2−2x−2log(x−1)
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Add the constant of integration:
2x2log(x−1)−4x2−2x−2log(x−1)+constant
The answer is:
2x2log(x−1)−4x2−2x−2log(x−1)+constant
The answer (Indefinite)
[src]
/ 2 2
| x log(-1 + x) x x *log(x - 1)
| x*log(x - 1)*1 dx = C - - - ----------- - -- + -------------
| 2 2 4 2
/
2log(x−1)x2−22x2+2x+log(x−1)
42log(−1)−3
=
−43+2iπ
(-0.75 + 1.5707963267949j)
(-0.75 + 1.5707963267949j)
Use the examples entering the upper and lower limits of integration.