Thread: ln Harmonic function

1. ln Harmonic function

f(x,y)=ln(4x^2+4y^2) show that the function is a harmonic series.

2. Originally Posted by Link88
f(x,y)=ln(4x^2+4y^2) show that the function is a harmonic series.
Do you mean to show that the function is harmonic?

To do so, show that $f\!\left(x,y\right)$ satisfies Laplace's Equation $\frac{\partial^2 f}{\partial x^2}+\frac{\partial^2 f}{\partial y^2}=0$

Can you take it from here?

3. Well I took the derivatives of both fx and fy but got 2y + 2x = 0 which can't be it : /