# Help to solve differentail equation

#### Mekhala

##### New member
eliminate the arbitrary constants a & b from z^2 =ax^3 +by^3+ab

#### HallsofIvy

##### Elite Member
So this is NOT "solving" a differential equation, it is creating a differential equation.

The derivative of a constant is 0 so start differentiating!

Differentiate with respect to x
$$\displaystyle 2z\frac{\partial z}{\partial x}= 3ax^2$$

Differentiate again with respect to y
$$\displaystyle 2z\frac{\partial^2z}{\partial x\partial y}+ 2\frac{\partial z}{\partial x}\frac{\partial z}{\partial y}= 0$$