Why is arc length of a function [tex]f(x)[/tex] from a to b defined as [tex]\int_a^b \sqrt{1+(f'(x))^2} dx[/tex]?(adsbygoogle = window.adsbygoogle || []).push({});

Where they get the idea of squaring the derivative, adding 1, taking the square root, and then integrating it is beyond me.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Arc Length Confusion

**Physics Forums | Science Articles, Homework Help, Discussion**