I have to compute the arc length of

I found the formula *

I don't know how to do this integral.

Can you please help me?

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- December 11th 2008, 06:21 AMvincisonfirePath Integral
I have to compute the arc length of

I found the formula *

I don't know how to do this integral.

Can you please help me? - December 11th 2008, 07:19 AMSkalkaz
Dear vincisonfire,

one of tricks: cos(theta) = cos(2*(theta/2)) and

cos(2x) = cos^2(x)-sin^2(x). - December 11th 2008, 08:43 AMvincisonfire
I would have

Back to my problem *

I should have 8 no ? - December 11th 2008, 09:32 AMSkalkaz
khm...khm...

such in x = -3 - December 11th 2008, 10:04 AMgalactus
Integrate from 0 to Pi and multiply by 2.

- December 11th 2008, 01:17 PMSoroban
Hello, vincisonfire!

Quote:

I have to compute the arc length of

I found the formula: .

We're expected to know this identity: .

We have: .

Therefore: . . Got it?

- December 11th 2008, 03:59 PMSkalkaz
http://www.mathhelpforum.com/math-he...95161f38-1.gif

It is not true!

See above!

- December 11th 2008, 04:45 PMKrizalid