Integral of cos^5x/sin^2x dx
The solution
Detail solution
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Rewrite the integrand:
sin2(x)cos5(x)=sin2(x)(1−sin2(x))2cos(x)
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There are multiple ways to do this integral.
Method #1
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Let u=sin(x).
Then let du=cos(x)dx and substitute du:
∫u2u4−2u2+1du
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Rewrite the integrand:
u2u4−2u2+1=u2−2+u21
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Integrate term-by-term:
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The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
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The integral of a constant is the constant times the variable of integration:
∫(−2)du=−2u
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The integral of un is n+1un+1 when n=−1:
∫u21du=−u1
The result is: 3u3−2u−u1
Now substitute u back in:
3sin3(x)−2sin(x)−sin(x)1
Method #2
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Rewrite the integrand:
sin2(x)(1−sin2(x))2cos(x)=sin2(x)sin4(x)cos(x)−2sin2(x)cos(x)+cos(x)
-
Let u=sin(x).
Then let du=cos(x)dx and substitute du:
∫u2u4−2u2+1du
-
Rewrite the integrand:
u2u4−2u2+1=u2−2+u21
-
Integrate term-by-term:
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
-
The integral of a constant is the constant times the variable of integration:
∫(−2)du=−2u
-
The integral of un is n+1un+1 when n=−1:
∫u21du=−u1
The result is: 3u3−2u−u1
Now substitute u back in:
3sin3(x)−2sin(x)−sin(x)1
Method #3
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Rewrite the integrand:
sin2(x)(1−sin2(x))2cos(x)=sin2(x)cos(x)−2cos(x)+sin2(x)cos(x)
-
Integrate term-by-term:
-
Let u=sin(x).
Then let du=cos(x)dx and substitute du:
∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
Now substitute u back in:
3sin3(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−2cos(x))dx=−2∫cos(x)dx
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The integral of cosine is sine:
∫cos(x)dx=sin(x)
So, the result is: −2sin(x)
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Let u=sin(x).
Then let du=cos(x)dx and substitute du:
∫u21du
-
The integral of un is n+1un+1 when n=−1:
∫u21du=−u1
Now substitute u back in:
−sin(x)1
The result is: 3sin3(x)−2sin(x)−sin(x)1
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Add the constant of integration:
3sin3(x)−2sin(x)−sin(x)1+constant
The answer is:
3sin3(x)−2sin(x)−sin(x)1+constant
The answer (Indefinite)
[src]
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| 5 3
| cos (x) 1 sin (x)
| ------- dx = C - ------ - 2*sin(x) + -------
| 2 sin(x) 3
| sin (x)
|
/
3sin3x−6sinx−sinx1
The graph
Use the examples entering the upper and lower limits of integration.