Integral of (3-4*x)*sin5xdx 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:
(3−4x)sin(5x)=−4xsin(5x)+3sin(5x)
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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:
∫(−4xsin(5x))dx=−4∫xsin(5x)dx
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Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=x and let dv(x)=sin(5x).
Then du(x)=1.
To find v(x):
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5sin(u)du
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The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=5∫sin(u)du
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The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −5cos(u)
Now substitute u back in:
−5cos(5x)
Now evaluate the sub-integral.
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The integral of a constant times a function is the constant times the integral of the function:
∫(−5cos(5x))dx=−5∫cos(5x)dx
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=5∫cos(u)du
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The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 5sin(u)
Now substitute u back in:
5sin(5x)
So, the result is: −25sin(5x)
So, the result is: 54xcos(5x)−254sin(5x)
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The integral of a constant times a function is the constant times the integral of the function:
∫3sin(5x)dx=3∫sin(5x)dx
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=5∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −5cos(u)
Now substitute u back in:
−5cos(5x)
So, the result is: −53cos(5x)
The result is: 54xcos(5x)−254sin(5x)−53cos(5x)
Method #2
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=3−4x and let dv(x)=sin(5x).
Then du(x)=−4.
To find v(x):
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=5∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −5cos(u)
Now substitute u back in:
−5cos(5x)
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫54cos(5x)dx=54∫cos(5x)dx
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=5∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 5sin(u)
Now substitute u back in:
5sin(5x)
So, the result is: 254sin(5x)
Method #3
-
Rewrite the integrand:
(3−4x)sin(5x)=−4xsin(5x)+3sin(5x)
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−4xsin(5x))dx=−4∫xsin(5x)dx
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=x and let dv(x)=sin(5x).
Then du(x)=1.
To find v(x):
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=5∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −5cos(u)
Now substitute u back in:
−5cos(5x)
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−5cos(5x))dx=−5∫cos(5x)dx
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=5∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 5sin(u)
Now substitute u back in:
5sin(5x)
So, the result is: −25sin(5x)
So, the result is: 54xcos(5x)−254sin(5x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫3sin(5x)dx=3∫sin(5x)dx
-
Let u=5x.
Then let du=5dx and substitute 5du:
∫5sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=5∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −5cos(u)
Now substitute u back in:
−5cos(5x)
So, the result is: −53cos(5x)
The result is: 54xcos(5x)−254sin(5x)−53cos(5x)
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Add the constant of integration:
54xcos(5x)−254sin(5x)−53cos(5x)+constant
The answer is:
54xcos(5x)−254sin(5x)−53cos(5x)+constant
The answer (Indefinite)
[src]
/
| 4*sin(5*x) 3*cos(5*x) 4*x*cos(5*x)
| (3 - 4*x)*sin(5*x) dx = C - ---------- - ---------- + ------------
| 25 5 5
/
∫(3−4x)sin(5x)dx=C+54xcos(5x)−254sin(5x)−53cos(5x)
The graph
3 4*sin(5) cos(5)
- - -------- + ------
5 25 5
5cos(5)−254sin(5)+53
=
3 4*sin(5) cos(5)
- - -------- + ------
5 25 5
5cos(5)−254sin(5)+53
3/5 - 4*sin(5)/25 + cos(5)/5
Use the examples entering the upper and lower limits of integration.