Use implicit differentiation where LaTeX:  \displaystyle y is a function of LaTeX:  \displaystyle x to find the derivative of LaTeX:  \displaystyle 8 x^{2} e^{y} + 4 \log{\left(x \right)} \cos{\left(y^{2} \right)}=26

Taking the derivative of both sides using implicit differentiation gives: LaTeX:   8 x^{2} y' e^{y} + 16 x e^{y} - 8 y y' \log{\left(x \right)} \sin{\left(y^{2} \right)} + \frac{4 \cos{\left(y^{2} \right)}}{x} = 0  Solving for LaTeX:  \displaystyle y' gives LaTeX:  \displaystyle y' = - \frac{4 x^{2} e^{y} + \cos{\left(y^{2} \right)}}{2 x \left(x^{2} e^{y} - y \log{\left(x \right)} \sin{\left(y^{2} \right)}\right)}