Use implicit differentiation where LaTeX:  \displaystyle y is a function of LaTeX:  \displaystyle x to find the derivative of LaTeX:  \displaystyle - x \log{\left(y \right)} + 3 y \log{\left(x \right)}=34

Taking the derivative of both sides using implicit differentiation gives: LaTeX:   - \frac{x y'}{y} + 3 y' \log{\left(x \right)} - \log{\left(y \right)} + \frac{3 y}{x} = 0  Solving for LaTeX:  \displaystyle y' gives LaTeX:  \displaystyle y' = \frac{y \left(- x \log{\left(y \right)} + 3 y\right)}{x \left(x - 3 y \log{\left(x \right)}\right)}