# Math Help - vector field flow line calculation

1. ## vector field flow line calculation

And in the xy-plane, if the vector fields is given by <A, B> that means that dx/dt is a multiple of A and that dy/dt is that same multiple of B. And that means that $\frac{dy}{dx}= \left(\frac{dy}{dt}\right)/\left(\frac{dx}{dt}\right)= \frac{B}{A}$.
The result of all that, for this problem, is that $\frac{dy}{dx}= \frac{-\frac{x}{x^2+ y^2}}{\frac{y}{x^2+ y^2}}= -\frac{x}{y}$.