Vector Calculus Problems

Need HELP on a Vector Calculus Problem?

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

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