partial derivative

The second-order differential equation in an unknown function u: u(x, y) is defined as $\frac{\partial^2 u}{\partial x^2} = 2$. Assuming g:g(x), f: f(y), and h: h(y), the general s...

Consider two functions: x=ψlnφ and y=φlnψ. Which one of the following is the correct expression for ∂ψ/∂x?