Integral of tan^3(x)sec^7(x) dx
The solution
Detail solution
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Rewrite the integrand:
tan3(x)sec7(x)=(sec2(x)−1)tan(x)sec7(x)
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There are multiple ways to do this integral.
Method #1
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Let u=sec(x).
Then let du=tan(x)sec(x)dx and substitute du:
∫(u8−u6)du
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Integrate term-by-term:
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The integral of un is n+1un+1 when n=−1:
∫u8du=9u9
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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
The result is: 9u9−7u7
Now substitute u back in:
9sec9(x)−7sec7(x)
Method #2
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Rewrite the integrand:
(sec2(x)−1)tan(x)sec7(x)=tan(x)sec9(x)−tan(x)sec7(x)
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Integrate term-by-term:
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Let u=sec9(x).
Then let du=9tan(x)sec9(x)dx and substitute 9du:
∫811du
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The integral of a constant times a function is the constant times the integral of the function:
∫91du=9∫1du
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The integral of a constant is the constant times the variable of integration:
∫1du=u
So, the result is: 9u
Now substitute u back in:
9sec9(x)
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The integral of a constant times a function is the constant times the integral of the function:
∫(−tan(x)sec7(x))dx=−∫tan(x)sec7(x)dx
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Let u=sec7(x).
Then let du=7tan(x)sec7(x)dx and substitute 7du:
∫491du
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The integral of a constant times a function is the constant times the integral of the function:
∫71du=7∫1du
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The integral of a constant is the constant times the variable of integration:
∫1du=u
So, the result is: 7u
Now substitute u back in:
7sec7(x)
So, the result is: −7sec7(x)
The result is: 9sec9(x)−7sec7(x)
Method #3
-
Rewrite the integrand:
(sec2(x)−1)tan(x)sec7(x)=tan(x)sec9(x)−tan(x)sec7(x)
-
Integrate term-by-term:
-
Let u=sec9(x).
Then let du=9tan(x)sec9(x)dx and substitute 9du:
∫811du
-
The integral of a constant times a function is the constant times the integral of the function:
∫91du=9∫1du
-
The integral of a constant is the constant times the variable of integration:
∫1du=u
So, the result is: 9u
Now substitute u back in:
9sec9(x)
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−tan(x)sec7(x))dx=−∫tan(x)sec7(x)dx
-
Let u=sec7(x).
Then let du=7tan(x)sec7(x)dx and substitute 7du:
∫491du
-
The integral of a constant times a function is the constant times the integral of the function:
∫71du=7∫1du
-
The integral of a constant is the constant times the variable of integration:
∫1du=u
So, the result is: 7u
Now substitute u back in:
7sec7(x)
So, the result is: −7sec7(x)
The result is: 9sec9(x)−7sec7(x)
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Add the constant of integration:
9sec9(x)−7sec7(x)+constant
The answer is:
9sec9(x)−7sec7(x)+constant
The answer (Indefinite)
[src]
/
| 7 9
| 3 7 sec (x) sec (x)
| tan (x)*sec (x) dx = C - ------- + -------
| 7 9
/
−63cos9x9cos2x−7
The graph
2
2 7 - 9*cos (1)
-- + -------------
63 9
63*cos (1)
−7cos711+9cos911+632
=
2
2 7 - 9*cos (1)
-- + -------------
63 9
63*cos (1)
632+63cos9(1)7−9cos2(1)
Use the examples entering the upper and lower limits of integration.