Simple question in Del operator on plane wave equation

1. Oct 11, 2014

baby_1

Hello
question is:
As you see when we do del operator on A vector filed in below example it removes exponential form at the end.why does it remove exponential form finally?

2. Oct 11, 2014

vela

Staff Emeritus
It doesn't. The exponential is part of $\vec{A}$.