How Does Arc Length Calculation Relate to Surface Problems?

[nameVoid]

HELP

 

[Mark44]

What, are we supposed to guess what the problem is from the title on the thread? Presumably you want to find the arc length along the curve between points A and B.

What does this have to do with surfaces, though?

For the arc length, the integrand is sqrt(1 + (y')^2), which can be written as
\sqrt{1 + (\frac{x^2}{4} - \frac{1}{x^2})^2}
=\sqrt{1 + \frac{x^4}{16} -1/2 + \frac{1}{x^4}}

The last three terms under the radical are a perfect square. When you add the first term, you'll still have a perfect square, which makes it easy to take the square root, which means you'll have an easy function to integrate.