Use implicit differentiation where LaTeX:  \displaystyle y is a function of LaTeX:  \displaystyle x to find the derivative of LaTeX:  \displaystyle 21 \sqrt{y} \cos{\left(x^{3} \right)} + 4 \log{\left(y \right)} \sin{\left(x^{2} \right)}=41

Taking the derivative of both sides using implicit differentiation gives: LaTeX:   - 63 x^{2} \sqrt{y} \sin{\left(x^{3} \right)} + 8 x \log{\left(y \right)} \cos{\left(x^{2} \right)} + \frac{4 y' \sin{\left(x^{2} \right)}}{y} + \frac{21 y' \cos{\left(x^{3} \right)}}{2 \sqrt{y}} = 0  Solving for LaTeX:  \displaystyle y' gives LaTeX:  \displaystyle y' = \frac{2 x \left(63 x y^{2} \sin{\left(x^{3} \right)} - 8 y^{\frac{3}{2}} \log{\left(y \right)} \cos{\left(x^{2} \right)}\right)}{8 \sqrt{y} \sin{\left(x^{2} \right)} + 21 y \cos{\left(x^{3} \right)}}