Integral of cos^(2)7x dx
The solution
Detail solution
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Rewrite the integrand:
cos2(7x)=2cos(14x)+21
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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:
∫2cos(14x)dx=2∫cos(14x)dx
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Let u=14x.
Then let du=14dx and substitute 14du:
∫196cos(u)du
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The integral of a constant times a function is the constant times the integral of the function:
∫14cos(u)du=14∫cos(u)du
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The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 14sin(u)
Now substitute u back in:
14sin(14x)
So, the result is: 28sin(14x)
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The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+28sin(14x)
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Add the constant of integration:
2x+28sin(14x)+constant
The answer is:
2x+28sin(14x)+constant
The answer (Indefinite)
[src]
/
|
| 2 x sin(14*x)
| cos (7*x) dx = C + - + ---------
| 2 28
/
142sin(14x)+7x
The graph
1 cos(7)*sin(7)
- + -------------
2 14
28sin14+14
=
1 cos(7)*sin(7)
- + -------------
2 14
14sin(7)cos(7)+21
Use the examples entering the upper and lower limits of integration.