arc length

[silverbabe]

How do I solve this ?

[Werg22]

Weierstrass substitution.

[HallsofIvy]

i.e. a trig substitution.

[Defennder]

I didn't know that was called Weierstrass substitution. I've always known it as "t-formula".

[silverbabe]

okay..... I´m lost!

[Jitse Niesen]

Silverbabe, search for "Weierstrass substitution" or "trigonometric substitution" in your calculus book, library, the Internet, or Wikipedia, and you'll find out what it means