Integral of ((x^2+4x+3))*sin4x 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)+3)sin(4x)=x2sin(4x)+4xsin(4x)+3sin(4x)
-
Integrate term-by-term:
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=x2 and let dv(x)=sin(4x).
Then du(x)=2x.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
Now evaluate the sub-integral.
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=−2x and let dv(x)=cos(4x).
Then du(x)=−21.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4x)
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−8sin(4x))dx=−8∫sin(4x)dx
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
So, the result is: 32cos(4x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫4xsin(4x)dx=4∫xsin(4x)dx
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=x and let dv(x)=sin(4x).
Then du(x)=1.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−4cos(4x))dx=−4∫cos(4x)dx
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4x)
So, the result is: −16sin(4x)
So, the result is: −xcos(4x)+4sin(4x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫3sin(4x)dx=3∫sin(4x)dx
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
So, the result is: −43cos(4x)
The result is: −4x2cos(4x)+8xsin(4x)−xcos(4x)+4sin(4x)−3223cos(4x)
Method #2
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=x2+4x+3 and let dv(x)=sin(4x).
Then du(x)=2x+4.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
Now evaluate the sub-integral.
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=−2x−1 and let dv(x)=cos(4x).
Then du(x)=−21.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4x)
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−8sin(4x))dx=−8∫sin(4x)dx
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
So, the result is: 32cos(4x)
Method #3
-
Rewrite the integrand:
((x2+4x)+3)sin(4x)=x2sin(4x)+4xsin(4x)+3sin(4x)
-
Integrate term-by-term:
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=x2 and let dv(x)=sin(4x).
Then du(x)=2x.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
Now evaluate the sub-integral.
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=−2x and let dv(x)=cos(4x).
Then du(x)=−21.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4x)
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−8sin(4x))dx=−8∫sin(4x)dx
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
So, the result is: 32cos(4x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫4xsin(4x)dx=4∫xsin(4x)dx
-
Use integration by parts:
∫udv=uv−∫vdu
Let u(x)=x and let dv(x)=sin(4x).
Then du(x)=1.
To find v(x):
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
Now evaluate the sub-integral.
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−4cos(4x))dx=−4∫cos(4x)dx
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=4∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 4sin(u)
Now substitute u back in:
4sin(4x)
So, the result is: −16sin(4x)
So, the result is: −xcos(4x)+4sin(4x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫3sin(4x)dx=3∫sin(4x)dx
-
Let u=4x.
Then let du=4dx and substitute 4du:
∫4sin(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫sin(u)du=4∫sin(u)du
-
The integral of sine is negative cosine:
∫sin(u)du=−cos(u)
So, the result is: −4cos(u)
Now substitute u back in:
−4cos(4x)
So, the result is: −43cos(4x)
The result is: −4x2cos(4x)+8xsin(4x)−xcos(4x)+4sin(4x)−3223cos(4x)
-
Add the constant of integration:
−4x2cos(4x)+8xsin(4x)−xcos(4x)+4sin(4x)−3223cos(4x)+constant
The answer is:
−4x2cos(4x)+8xsin(4x)−xcos(4x)+4sin(4x)−3223cos(4x)+constant
The answer (Indefinite)
[src]
/
| 2
| / 2 \ 23*cos(4*x) sin(4*x) x *cos(4*x) x*sin(4*x)
| \x + 4*x + 3/*sin(4*x) dx = C - ----------- + -------- - x*cos(4*x) - ----------- + ----------
| 32 4 4 8
/
∫((x2+4x)+3)sin(4x)dx=C−4x2cos(4x)+8xsin(4x)−xcos(4x)+4sin(4x)−3223cos(4x)
The graph
23 cos(4) sin(4)
- -- - ------ + ------
32 32 8
−3223+8sin(4)−32cos(4)
=
23 cos(4) sin(4)
- -- - ------ + ------
32 32 8
−3223+8sin(4)−32cos(4)
-23/32 - cos(4)/32 + sin(4)/8
Use the examples entering the upper and lower limits of integration.