# Thread: Deriving the formula for the arc length of a cruve

1. ## Deriving the formula for the arc length of a cruve

Hi there,
I understand everything except until moving from the limit that leads to the Riemann integral that measures the arc length. Is it possible for someone to explain this to me?

Calculus II - Arc Length

2. ## Re: Deriving the formula for the arc length of a cruve

The last step, converting from a sum to an integral, is simply the Riemann sum definition of the integral. Riemann Integral -- from Wolfram MathWorld