Integral of x*log^3*x dx
The solution
Detail solution
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Let u=log(x).
Then let du=xdx and substitute du:
∫u3e2udu
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Use integration by parts:
∫udv=uv−∫vdu
Let u(u)=u3 and let dv(u)=e2u.
Then du(u)=3u2.
To find v(u):
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Let u=2u.
Then let du=2du and substitute 2du:
∫2eudu
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The integral of a constant times a function is the constant times the integral of the function:
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The integral of the exponential function is itself.
∫eudu=eu
So, the result is: 2eu
Now substitute u back in:
2e2u
Now evaluate the sub-integral.
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Use integration by parts:
∫udv=uv−∫vdu
Let u(u)=23u2 and let dv(u)=e2u.
Then du(u)=3u.
To find v(u):
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2eudu
-
The integral of a constant times a function is the constant times the integral of the function:
-
The integral of the exponential function is itself.
∫eudu=eu
So, the result is: 2eu
Now substitute u back in:
2e2u
Now evaluate the sub-integral.
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(u)=23u and let dv(u)=e2u.
Then du(u)=23.
To find v(u):
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2eudu
-
The integral of a constant times a function is the constant times the integral of the function:
-
The integral of the exponential function is itself.
∫eudu=eu
So, the result is: 2eu
Now substitute u back in:
2e2u
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫43e2udu=43∫e2udu
-
Let u=2u.
Then let du=2du and substitute 2du:
∫2eudu
-
The integral of a constant times a function is the constant times the integral of the function:
-
The integral of the exponential function is itself.
∫eudu=eu
So, the result is: 2eu
Now substitute u back in:
2e2u
So, the result is: 83e2u
Now substitute u back in:
2x2log(x)3−43x2log(x)2+43x2log(x)−83x2
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Now simplify:
8x2(4log(x)3−6log(x)2+6log(x)−3)
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Add the constant of integration:
8x2(4log(x)3−6log(x)2+6log(x)−3)+constant
The answer is:
8x2(4log(x)3−6log(x)2+6log(x)−3)+constant
The answer (Indefinite)
[src]
/
| 2 2 3 2 2 2
| 3 3*x x *log (x) 3*x *log (x) 3*x *log(x)
| x*log (x) dx = C - ---- + ---------- - ------------ + -----------
| 8 2 4 4
/
∫xlog(x)3dx=C+2x2log(x)3−43x2log(x)2+43x2log(x)−83x2
The graph
Use the examples entering the upper and lower limits of integration.