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beef
Registered User regular

I'm doing a Lagrangian problem, and I'm having trouble remembering polar coordinate stuff.

Specifically, what would be the derivative of theta dot squared with respect to theta?

And what would be the time derivative of theta dot squared?

Also, both of the above questions with*r* in place of theta?

I've been looking at Wikipedia and Wolfram and not finding either to be much help.

Specifically, what would be the derivative of theta dot squared with respect to theta?

And what would be the time derivative of theta dot squared?

Also, both of the above questions with

I've been looking at Wikipedia and Wolfram and not finding either to be much help.

0

## Posts

so you need to use your rules for partial derviatives.

If i have some function f(x) then want to find its partial derivative with respect to y, what usually happens?

as well, what happens to f(x) when i want some d/dx.

solutions

d/dt of thetadot^2 should be 1/2thetadot

if you swap in r and still want d/dtheta and d/dt, thats gonna be zero, as r is usually r(x).

Fuzzywhaleon