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Basic Integration problem

  • #1
Krushnaraj Pandya
Gold Member
697
71

Homework Statement


∫(√x)^5/((√x)^7+x^6) dx

Homework Equations


I have learned integration through substitution, trigonometric identities and standard integrals

The Attempt at a Solution


I took (√x)^5 common which gave 1/(x+√x^7), Then I tried to substitute √x=t, √x^7=t but it just seems to complicate things more, I don't see any fruitful trigonometric substitutions either- would be grateful if someone can tell me how to proceed
 

Answers and Replies

  • #2
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4,965

Homework Statement


∫(√x)^5/((√x)^7+x^6) dx

Homework Equations


I have learned integration through substitution, trigonometric identities and standard integrals

The Attempt at a Solution


I took (√x)^5 common which gave 1/(x+√x^7), Then I tried to substitute √x=t, √x^7=t but it just seems to complicate things more, I don't see any fruitful trigonometric substitutions either- would be grateful if someone can tell me how to proceed
Your substitution should work.
##t = x^{1/2} \Rightarrow t^2 = x \Rightarrow 2tdt = dx##
After you make the substitution, you should get an integral that you can evaluate using partial fractions.
 
  • #3
Krushnaraj Pandya
Gold Member
697
71
Your substitution should work.
##t = x^{1/2} \Rightarrow t^2 = x \Rightarrow 2tdt = dx##
After you make the substitution, you should get an integral that you can evaluate using partial fractions.
The exercise in my textbook is supposed to be using the concepts I mentioned under relevant equations, therefore I need to solve it using that
 
  • #4
Ray Vickson
Science Advisor
Homework Helper
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The exercise in my textbook is supposed to be using the concepts I mentioned under relevant equations, therefore I need to solve it using that
Mark44 IS suggesting a method on your list---substitution. After that, partial fractions are a 100% standard method, and anybody who tells you you cannot use them is doing you a dis-service. Some integrals just cannot be done in any other way (except, maybe, by finding them in some "tables of integrals" somewhere).
 
  • #5
Krushnaraj Pandya
Gold Member
697
71
Mark44 IS suggesting a method on your list---substitution. After that, partial fractions are a 100% standard method, and anybody who tells you you cannot use them is doing you a dis-service. Some integrals just cannot be done in any other way (except, maybe, by finding them in some "tables of integrals" somewhere).
ohh...ok, I'll use that then and see if I can solve it
 
  • #6
Krushnaraj Pandya
Gold Member
697
71
Mark44 IS suggesting a method on your list---substitution. After that, partial fractions are a 100% standard method, and anybody who tells you you cannot use them is doing you a dis-service. Some integrals just cannot be done in any other way (except, maybe, by finding them in some "tables of integrals" somewhere).
I got the correct answer. Thanks a lot!
 

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