Use implicit differentiation where LaTeX:  \displaystyle y is a function of LaTeX:  \displaystyle x to find the derivative of LaTeX:  \displaystyle 14 \sqrt{x} \cos{\left(y^{3} \right)} - 2 x^{2} \sqrt{y}=-23

Taking the derivative of both sides using implicit differentiation gives: LaTeX:   - 42 \sqrt{x} y^{2} y' \sin{\left(y^{3} \right)} - \frac{x^{2} y'}{\sqrt{y}} - 4 x \sqrt{y} + \frac{7 \cos{\left(y^{3} \right)}}{\sqrt{x}} = 0  Solving for LaTeX:  \displaystyle y' gives LaTeX:  \displaystyle y' = \frac{- 4 x^{\frac{3}{2}} y + 7 \sqrt{y} \cos{\left(y^{3} \right)}}{x^{\frac{5}{2}} + 42 x y^{\frac{5}{2}} \sin{\left(y^{3} \right)}}