Integral of (sinx-cosx)^2 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:
(sin(x)−cos(x))2=sin2(x)−2sin(x)cos(x)+cos2(x)
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Integrate term-by-term:
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Rewrite the integrand:
sin2(x)=21−2cos(2x)
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Integrate term-by-term:
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The integral of a constant is the constant times the variable of integration:
∫21dx=2x
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The integral of a constant times a function is the constant times the integral of the function:
∫(−2cos(2x))dx=−2∫cos(2x)dx
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Let u=2x.
Then let du=2dx and substitute 2du:
∫2cos(u)du
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The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
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The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2x)
So, the result is: −4sin(2x)
The result is: 2x−4sin(2x)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−2sin(x)cos(x))dx=−2∫sin(x)cos(x)dx
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There are multiple ways to do this integral.
Method #1
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫(−u)du
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The integral of a constant times a function is the constant times the integral of the function:
∫udu=−∫udu
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The integral of un is n+1un+1 when n=−1:
∫udu=2u2
So, the result is: −2u2
Now substitute u back in:
−2cos2(x)
Method #2
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Let u=sin(x).
Then let du=cos(x)dx and substitute du:
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The integral of un is n+1un+1 when n=−1:
∫udu=2u2
Now substitute u back in:
2sin2(x)
So, the result is: cos2(x)
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Rewrite the integrand:
cos2(x)=2cos(2x)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2x)dx=2∫cos(2x)dx
-
Let u=2x.
Then let du=2dx and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2x)
So, the result is: 4sin(2x)
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+4sin(2x)
The result is: x+cos2(x)
Method #2
-
Rewrite the integrand:
(sin(x)−cos(x))2=sin2(x)−2sin(x)cos(x)+cos2(x)
-
Integrate term-by-term:
-
Rewrite the integrand:
sin2(x)=21−2cos(2x)
-
Integrate term-by-term:
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−2cos(2x))dx=−2∫cos(2x)dx
-
Let u=2x.
Then let du=2dx and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2x)
So, the result is: −4sin(2x)
The result is: 2x−4sin(2x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−2sin(x)cos(x))dx=−2∫sin(x)cos(x)dx
-
Let u=cos(x).
Then let du=−sin(x)dx and substitute −du:
∫(−u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫udu=−∫udu
-
The integral of un is n+1un+1 when n=−1:
∫udu=2u2
So, the result is: −2u2
Now substitute u back in:
−2cos2(x)
So, the result is: cos2(x)
-
Rewrite the integrand:
cos2(x)=2cos(2x)+21
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫2cos(2x)dx=2∫cos(2x)dx
-
Let u=2x.
Then let du=2dx and substitute 2du:
∫2cos(u)du
-
The integral of a constant times a function is the constant times the integral of the function:
∫cos(u)du=2∫cos(u)du
-
The integral of cosine is sine:
∫cos(u)du=sin(u)
So, the result is: 2sin(u)
Now substitute u back in:
2sin(2x)
So, the result is: 4sin(2x)
-
The integral of a constant is the constant times the variable of integration:
∫21dx=2x
The result is: 2x+4sin(2x)
The result is: x+cos2(x)
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Add the constant of integration:
x+cos2(x)+constant
The answer is:
x+cos2(x)+constant
The answer (Indefinite)
[src]
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| 2 2
| (sin(x) - cos(x)) dx = C + x + cos (x)
|
/
∫(sin(x)−cos(x))2dx=C+x+cos2(x)
The graph
cos2(1)
=
cos2(1)
Use the examples entering the upper and lower limits of integration.