Integral of sin(5x)cos(2x)dx dx
The solution
Detail solution
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Rewrite the integrand:
sin(5x)cos(2x)1=32sin5(x)cos2(x)−16sin5(x)−40sin3(x)cos2(x)+20sin3(x)+10sin(x)cos2(x)−5sin(x)
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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:
∫32sin5(x)cos2(x)dx=32∫sin5(x)cos2(x)dx
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Rewrite the integrand:
sin5(x)cos2(x)=(1−cos2(x))2sin(x)cos2(x)
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There are multiple ways to do this integral.
Method #1
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Let u=cos(x).
Then let du=−sin(x)dx and substitute du:
∫(−u6+2u4−u2)du
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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:
∫(−u6)du=−∫u6du
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The integral of un is n+1un+1 when n=−1:
∫u6du=7u7
So, the result is: −7u7
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The integral of a constant times a function is the constant times the integral of the function:
∫2u4du=2∫u4du
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The integral of un is n+1un+1 when n=−1:
∫u4du=5u5
So, the result is: 52u5
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The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
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The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
The result is: −7u7+52u5−3u3
Now substitute u back in:
−7cos7(x)+52cos5(x)−3cos3(x)
Method #2
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Rewrite the integrand:
(1−cos2(x))2sin(x)cos2(x)=sin(x)cos6(x)−2sin(x)cos4(x)+sin(x)cos2(x)
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Integrate term-by-term:
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u6du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u6)du=−∫u6du
-
The integral of un is n+1un+1 when n=−1:
∫u6du=7u7
So, the result is: −7u7
Now substitute u back in:
−7cos7(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−2sin(x)cos4(x))dx=−2∫sin(x)cos4(x)dx
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Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u4du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u4)du=−∫u4du
-
The integral of un is n+1un+1 when n=−1:
∫u4du=5u5
So, the result is: −5u5
Now substitute u back in:
−5cos5(x)
So, the result is: 52cos5(x)
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Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u2du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
Now substitute u back in:
−3cos3(x)
The result is: −7cos7(x)+52cos5(x)−3cos3(x)
Method #3
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Rewrite the integrand:
(1−cos2(x))2sin(x)cos2(x)=sin(x)cos6(x)−2sin(x)cos4(x)+sin(x)cos2(x)
-
Integrate term-by-term:
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u6du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u6)du=−∫u6du
-
The integral of un is n+1un+1 when n=−1:
∫u6du=7u7
So, the result is: −7u7
Now substitute u back in:
−7cos7(x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−2sin(x)cos4(x))dx=−2∫sin(x)cos4(x)dx
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u4du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u4)du=−∫u4du
-
The integral of un is n+1un+1 when n=−1:
∫u4du=5u5
So, the result is: −5u5
Now substitute u back in:
−5cos5(x)
So, the result is: 52cos5(x)
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u2du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
Now substitute u back in:
−3cos3(x)
The result is: −7cos7(x)+52cos5(x)−3cos3(x)
So, the result is: −732cos7(x)+564cos5(x)−332cos3(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−16sin5(x))dx=−16∫sin5(x)dx
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Rewrite the integrand:
sin5(x)=(1−cos2(x))2sin(x)
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Rewrite the integrand:
(1−cos2(x))2sin(x)=sin(x)cos4(x)−2sin(x)cos2(x)+sin(x)
-
Integrate term-by-term:
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u4du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u4)du=−∫u4du
-
The integral of un is n+1un+1 when n=−1:
∫u4du=5u5
So, the result is: −5u5
Now substitute u back in:
−5cos5(x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−2sin(x)cos2(x))dx=−2∫sin(x)cos2(x)dx
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u2du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
Now substitute u back in:
−3cos3(x)
So, the result is: 32cos3(x)
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The integral of sine is negative cosine:
∫sin(x)dx=−cos(x)
The result is: −5cos5(x)+32cos3(x)−cos(x)
So, the result is: 516cos5(x)−332cos3(x)+16cos(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−40sin3(x)cos2(x))dx=−40∫sin3(x)cos2(x)dx
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Rewrite the integrand:
sin3(x)cos2(x)=(1−cos2(x))sin(x)cos2(x)
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Let u=cos(x).
Then let du=−sin(x)dx and substitute du:
∫(u4−u2)du
-
Integrate term-by-term:
-
The integral of un is n+1un+1 when n=−1:
∫u4du=5u5
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
The result is: 5u5−3u3
Now substitute u back in:
5cos5(x)−3cos3(x)
So, the result is: −8cos5(x)+340cos3(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫20sin3(x)dx=20∫sin3(x)dx
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Rewrite the integrand:
sin3(x)=(1−cos2(x))sin(x)
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Let u=cos(x).
Then let du=−sin(x)dx and substitute du:
∫(u2−1)du
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Integrate term-by-term:
-
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:
∫(−1)du=−u
The result is: 3u3−u
Now substitute u back in:
3cos3(x)−cos(x)
So, the result is: 320cos3(x)−20cos(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫10sin(x)cos2(x)dx=10∫sin(x)cos2(x)dx
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫u2du
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−u2)du=−∫u2du
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
So, the result is: −3u3
Now substitute u back in:
−3cos3(x)
So, the result is: −310cos3(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−5sin(x))dx=−5∫sin(x)dx
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The integral of sine is negative cosine:
∫sin(x)dx=−cos(x)
So, the result is: 5cos(x)
The result is: −732cos7(x)+8cos5(x)−314cos3(x)+cos(x)
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Now simplify:
21(−96cos6(x)+168cos4(x)−98cos2(x)+21)cos(x)
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Add the constant of integration:
21(−96cos6(x)+168cos4(x)−98cos2(x)+21)cos(x)+constant
The answer is:
21(−96cos6(x)+168cos4(x)−98cos2(x)+21)cos(x)+constant
The answer (Indefinite)
[src]
/ 7 3
| 5 32*cos (x) 14*cos (x)
| sin(5*x)*cos(2*x)*1 dx = C + 8*cos (x) - ---------- - ---------- + cos(x)
| 7 3
/
−14cos(7x)−6cos(3x)
The graph
5 5*cos(2)*cos(5) 2*sin(2)*sin(5)
-- - --------------- - ---------------
21 21 21
215−423cos7+7cos3
=
5 5*cos(2)*cos(5) 2*sin(2)*sin(5)
-- - --------------- - ---------------
21 21 21
−215cos(2)cos(5)−212sin(2)sin(5)+215
Use the examples entering the upper and lower limits of integration.