Please help me integrate homework

  • Thread starter Davidk1
  • Start date
  • #1
3
0
Please help me integrate homework :(

[/tex]

Homework Statement





Homework Equations


\int dx/(1-x^2)^3

The Attempt at a Solution



I believe I have to use partial fractions to solve this integral. I started out by expanding the denominator

1/-(1 - 3x^2 + 3x^4 - x^6)

I pulled out a negative then separated by polynomial

x^4 (x^2 + 3) - 3(x^2 + 3) - 8

so:
-(x^4 - 3)(x^2 + 3) - 8

I'm lost..I need help

Homework Statement





Homework Equations





The Attempt at a Solution

 

Answers and Replies

  • #2
HallsofIvy
Science Advisor
Homework Helper
41,847
966


[/tex]

Homework Statement





Homework Equations


\int dx/(1-x^2)^3

The Attempt at a Solution



I believe I have to use partial fractions to solve this integral. I started out by expanding the denominator

1/-(1 - 3x^2 + 3x^4 - x^6)
Why in the world would you expand it? You want to factor it. It is already partly factored, don't throw that away! 1- x2= (1- x)(1+ x) so
(1-x2)3= (1- x)3(1+ x)3

[tex]\frac{1}{(1- x^2)^3}= \frac{A}{1-x}+ \frac{B}{(1-x)^2}+ \frac{C}{(1- x)^3}+ \frac{D}{1+ x}+ \frac{E}{(1+x)^2}+ \frac{F}{(1+x)^3}[/tex]

I pulled out a negative then separated by polynomial

x^4 (x^2 + 3) - 3(x^2 + 3) - 8

so:
-(x^4 - 3)(x^2 + 3) - 8

I'm lost..I need help

Homework Statement





Homework Equations





The Attempt at a Solution

 
  • #3
3
0


Thank You! I know I can solve it now!
 

Related Threads on Please help me integrate homework

  • Last Post
Replies
11
Views
870
  • Last Post
Replies
1
Views
890
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
6
Views
1K
Replies
7
Views
1K
  • Last Post
Replies
13
Views
2K
  • Last Post
Replies
2
Views
780
Replies
6
Views
2K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
12
Views
1K
Top