# Lengths of Plane Curves

• Feb 24th 2009, 04:08 PM
TAG16
Lengths of Plane Curves
Find the length of the curve:
x= (y^4)/4 + 1/(8y^2) from y=1 to y=2

I'm having trouble finding dx/dy
• Feb 24th 2009, 04:30 PM
skeeter
Quote:

Originally Posted by TAG16
Find the length of the curve:
x= (y^4)/4 + 1/(8y^2) from y=1 to y=2

I'm having trouble finding dx/dy

$y = \frac{1}{4}y^4 + \frac{1}{8}y^{-2}$

$\frac{dx}{dy} = y^3 - \frac{1}{4y^3}$

can you finish?
• Feb 24th 2009, 04:59 PM
TAG16
yeah, thats actually what I had I just didn't think I was right. thanks