Arc length integral

  • Thread starter hachi_roku
  • Start date
  • #1
61
0

Homework Statement



ok, the original prob is : find the length of the curve of y=ln(1-x^2) x between 0, 1/2.



Homework Equations





The Attempt at a Solution


ive made it this far: my integral is -1 + 2/1-x^2..............ok so i decompose the second part but in doing so i get a negative to make it -(x+1)(x-1) but i don't know what happens to that negative because the solution manual says the integral is .......-1+ 1/x+1 -1/x-1 dx i don't get the signs. please help!
 

Answers and Replies

  • #2
1,631
4
if we are woking with single variable functions, y=f(x) like here then the arc length from a to be of a curve is:


[tex]L=\int_a^b\sqrt{1+[f'(x)]^2}dx[/tex]
 
  • #3
61
0
yes....like i said ive already worked that part....im toward the end of the problem i just don't get the signs
 
  • #4
1,631
4
yes....like i said ive already worked that part....im toward the end of the problem i just don't get the signs

Well, since you have shown almost no work(step by step) it is hard to tell where you have missed, or what you are doing wrong.
 
  • #5
61
0
got it...nvm..thanks
 
  • #6
1,631
4

Related Threads on Arc length integral

  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
8
Views
1K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
13
Views
2K
  • Last Post
Replies
1
Views
858
  • Last Post
Replies
2
Views
2K
Replies
6
Views
2K
Replies
5
Views
2K
  • Last Post
Replies
6
Views
5K
Replies
4
Views
4K
Top