Integral of xln(x^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=log(x2).
Then let du=x2dx and substitute 2du:
∫4ueudu
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The integral of a constant times a function is the constant times the integral of the function:
∫2ueudu=2∫ueudu
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Use integration by parts:
∫udv=uv−∫vdu
Let u(u)=u and let dv(u)=eu.
Then du(u)=1.
To find v(u):
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The integral of the exponential function is itself.
∫eudu=eu
Now evaluate the sub-integral.
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The integral of the exponential function is itself.
∫eudu=eu
So, the result is: 2ueu−2eu
Now substitute u back in:
2x2log(x2)−2x2
Method #2
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Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=log(x2) and let dv(x)=x.
Then du(x)=x2.
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 xn is n+1xn+1 when n=−1:
∫xdx=2x2
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Now simplify:
2x2(log(x2)−1)
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Add the constant of integration:
2x2(log(x2)−1)+constant
The answer is:
2x2(log(x2)−1)+constant
The answer (Indefinite)
[src]
/
| 2 2 / 2\
| / 2\ x x *log\x /
| x*log\x / dx = C - -- + ----------
| 2 2
/
2(2x2logx−4x2)
Use the examples entering the upper and lower limits of integration.