laplacian equation notation Evans

79 Views Asked by At

enter image description here

I am wondering what does $\Delta_x \Phi(x-y)$ really mean? I come cross the claim that $\Delta_x \Phi(x-y)=\Delta_y \Phi(x-y)$. I am hoping anyone could help me explain that.

1

There are 1 best solutions below

2
On BEST ANSWER

We can write $$ \Delta_x \Phi(x-y)=\Delta \Phi(\cdot-y)(x) $$ or $$ \Delta_x \Phi(x-y)=\Delta F(x) , $$ where $$ F(x) = \Phi(x-y) . $$