Integral of 1/x*(lnx-1)^2 dx
The solution
Detail solution
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There are multiple ways to do this integral.
Method #1
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Let u=x1.
Then let du=−x2dx and substitute −du:
∫(−ulog(u1)2−2log(u1)+1)du
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The integral of a constant times a function is the constant times the integral of the function:
∫ulog(u1)2−2log(u1)+1du=−∫ulog(u1)2−2log(u1)+1du
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Let u=u1.
Then let du=−u2du and substitute −du:
∫(−ulog(u)2−2log(u)+1)du
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The integral of a constant times a function is the constant times the integral of the function:
∫ulog(u)2−2log(u)+1du=−∫ulog(u)2−2log(u)+1du
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Let u=log(u).
Then let du=udu and substitute du:
∫(u2−2u+1)du
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Integrate term-by-term:
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The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
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The integral of a constant times a function is the constant times the integral of the function:
∫(−2u)du=−2∫udu
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The integral of un is n+1un+1 when n=−1:
∫udu=2u2
So, the result is: −u2
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The integral of a constant is the constant times the variable of integration:
∫1du=u
The result is: 3u3−u2+u
Now substitute u back in:
3log(u)3−log(u)2+log(u)
So, the result is: −3log(u)3+log(u)2−log(u)
Now substitute u back in:
3log(u)3+log(u)2+log(u)
So, the result is: −3log(u)3−log(u)2−log(u)
Now substitute u back in:
3log(x)3−log(x)2+log(x)
Method #2
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Rewrite the integrand:
x(log(x)−1)2=xlog(x)2−2log(x)+1
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Let u=x1.
Then let du=−x2dx and substitute −du:
∫(−ulog(u1)2−2log(u1)+1)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫ulog(u1)2−2log(u1)+1du=−∫ulog(u1)2−2log(u1)+1du
-
Let u=log(u1).
Then let du=−udu and substitute du:
∫(−u2+2u−1)du
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Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
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The integral of a constant times a function is the constant times the integral of the function:
∫2udu=2∫udu
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The integral of un is n+1un+1 when n=−1:
∫udu=2u2
So, the result is: u2
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The integral of a constant is the constant times the variable of integration:
∫(−1)du=−u
The result is: −3u3+u2−u
Now substitute u back in:
−3log(u1)3+log(u1)2−log(u1)
So, the result is: 3log(u1)3−log(u1)2+log(u1)
Now substitute u back in:
3log(x)3−log(x)2+log(x)
Method #3
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Rewrite the integrand:
x(log(x)−1)2=xlog(x)2−x2log(x)+x1
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Integrate term-by-term:
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Let u=x1.
Then let du=−x2dx and substitute −du:
∫(−ulog(u1)2)du
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The integral of a constant times a function is the constant times the integral of the function:
∫ulog(u1)2du=−∫ulog(u1)2du
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Let u=log(u1).
Then let du=−udu and substitute −du:
∫(−u2)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫u2du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
Now substitute u back in:
−3log(u1)3
So, the result is: 3log(u1)3
Now substitute u back in:
3log(x)3
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The integral of a constant times a function is the constant times the integral of the function:
∫(−x2log(x))dx=−2∫xlog(x)dx
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Let u=x1.
Then let du=−x2dx and substitute −du:
∫(−ulog(u1))du
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The integral of a constant times a function is the constant times the integral of the function:
∫ulog(u1)du=−∫ulog(u1)du
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Let u=log(u1).
Then let du=−udu and substitute −du:
∫(−u)du
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The integral of a constant times a function is the constant times the integral of the function:
∫udu=−∫udu
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The integral of un is n+1un+1 when n=−1:
∫udu=2u2
So, the result is: −2u2
Now substitute u back in:
−2log(u1)2
So, the result is: 2log(u1)2
Now substitute u back in:
2log(x)2
So, the result is: −log(x)2
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The integral of x1 is log(x).
The result is: 3log(x)3−log(x)2+log(x)
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Now simplify:
(3log(x)2−log(x)+1)log(x)
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Add the constant of integration:
(3log(x)2−log(x)+1)log(x)+constant
The answer is:
(3log(x)2−log(x)+1)log(x)+constant
The answer (Indefinite)
[src]
/
|
| 2 3
| (log(x) - 1) 2 log (x)
| ------------- dx = C - log (x) + ------- + log(x)
| x 3
|
/
∫x(log(x)−1)2dx=C+3log(x)3−log(x)2+log(x)
The graph
Use the examples entering the upper and lower limits of integration.