Need HELP on a **Vector Calculus Problem**?

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*how do you solve this d/dx ((x )dtheta/dx) = 0 for theta? I forgot how to do vector calculus. This isn’t exactly my problem so i’d like to know the steps more than teh solution *

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If the derivative (with respect to x) of some expression equals 0, that means it doesn’t change with x — that is, it’s a constant. So d/dx ((x)d(theta)/dx) = 0 implies that x(d(theta)/dx) = c where c is a constant. Divide both sides by x and integrate again.

**Lecture 3: Vector Calculus: What is a vector field?? Chris Tisdell UNSW**