- #1
Trapezoid
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Homework Statement
My question is not specific to any particular problem but is rather of a conceptual nature. In my advanced calculus class this semester, the notation ds appears often, for line integrals, surface integrals, and arc length. In all honestly, I don't really understand what ds is and, as such, have had a lot of trouble solving problems involving it. Furthermore, while I know all of the formulas, I don't really understand how or why they work. Could somebody help me out on this one?
Homework Equations
arc length:
[tex]ds = \sqrt{ \left( \frac{dy}{dx} \right) ^2 + 1} [/tex]
surface integral: [tex]\int \int f(x, y, z) dS = \int \int f(x, y, g(x, y)) \sqrt{\left( \frac{\partial g}{\partial x} \right) ^2 + \left( \frac{\partial g}{\partial y} \right) ^2 + 1} \: dA[/tex]
The Attempt at a Solution
As far as I can tell, the element ds seems always to reduce the dimension of the function by 1. Perhaps it represents a projection onto that dimension? Obviously, if it's used to calculate surface area of solids and arc length of 2D functions, something like that must be going on, right? Am I on the right track?
Thanks,
Trapezoid