Integral of (cos(lnx))*(dx/x) 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(x).
Then let du=xdx and substitute du:
∫cos(u)du
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The integral of cosine is sine:
∫cos(u)du=sin(u)
Now substitute u back in:
sin(log(x))
Method #2
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Let u=x1.
Then let du=−x2dx and substitute −du:
∫ucos(log(u1))du
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The integral of a constant times a function is the constant times the integral of the function:
∫(−ucos(log(u1)))du=−∫ucos(log(u1))du
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Let u=log(u1).
Then let du=−udu and substitute −du:
∫cos(u)du
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The integral of a constant times a function is the constant times the integral of the function:
∫(−cos(u))du=−∫cos(u)du
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The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: −sin(u)
Now substitute u back in:
−sin(log(u1))
So, the result is: sin(log(u1))
Now substitute u back in:
sin(log(x))
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Add the constant of integration:
sin(log(x))+constant
The answer is:
sin(log(x))+constant
The answer (Indefinite)
[src]
/
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| 1
| cos(log(x))*1*- dx = C + sin(log(x))
| x
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/
sinlogx
∫01xcoslogxdx
=
⟨−1,1⟩
Use the examples entering the upper and lower limits of integration.