Integral of (x-1)/(x^2-4) dx
The solution
Detail solution
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There are multiple ways to do this integral.
Method #1
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Rewrite the integrand:
x2−4x−1=4(x+2)3+4(x−2)1
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Integrate term-by-term:
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The integral of a constant times a function is the constant times the integral of the function:
∫4(x+2)3dx=43∫x+21dx
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Let u=x+2.
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+2)
So, the result is: 43log(x+2)
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The integral of a constant times a function is the constant times the integral of the function:
∫4(x−2)1dx=4∫x−21dx
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Let u=x−2.
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−2)
So, the result is: 4log(x−2)
The result is: 4log(x−2)+43log(x+2)
Method #2
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Rewrite the integrand:
x2−4x−1=x2−4x−x2−41
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Integrate term-by-term:
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The integral of a constant times a function is the constant times the integral of the function:
∫x2−4xdx=2∫x2−42xdx
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Let u=x2−4.
Then let du=2xdx and substitute 2du:
∫2u1du
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The integral of u1 is log(u).
Now substitute u back in:
log(x2−4)
So, the result is: 2log(x2−4)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−x2−41)dx=−∫x2−41dx
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Rewrite the integrand:
x2−41=4−x+21+x−21
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The integral of a constant times a function is the constant times the integral of the function:
∫4−x+21+x−21dx=4∫(−x+21+x−21)dx
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Integrate term-by-term:
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The integral of x−21 is log(x−2).
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The integral of a constant times a function is the constant times the integral of the function:
∫(−x+21)dx=−∫x+21dx
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The integral of x+21 is log(x+2).
So, the result is: −log(x+2)
The result is: log(x−2)−log(x+2)
So, the result is: 4log(x−2)−4log(x+2)
So, the result is: −4log(x−2)+4log(x+2)
The result is: −4log(x−2)+4log(x+2)+2log(x2−4)
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Add the constant of integration:
4log(x−2)+43log(x+2)+constant
The answer is:
4log(x−2)+43log(x+2)+constant
The answer (Indefinite)
[src]
/
|
| x - 1 log(-2 + x) 3*log(2 + x)
| ------ dx = C + ----------- + ------------
| 2 4 4
| x - 4
|
/
∫x2−4x−1dx=C+4log(x−2)+43log(x+2)
The graph
3*log(3)
-log(2) + --------
4
−log(2)+43log(3)
=
3*log(3)
-log(2) + --------
4
−log(2)+43log(3)
Use the examples entering the upper and lower limits of integration.