- #1

- 1,996

- 1

**[SOLVED] Griffiths page 182**

**1. Homework Statement**

This question refers to Griffiths E and M book.

This page has been confusing me immensely over the past two days. First, can someone explain the logic in the statement below Figure 4.21 "so D can be found from the free charge as though the dielectric were not there". I do not understand at all the justification for the equation that follows.

Furthermore, what is most confusing to me is when we can assume the curl of D vanishes. Griffiths makes it seem like this is almost never true, but then in all of the problems he uses this fact like in Example 4.6. Can someone explain why he uses this fact in Example 4.6 and also when I can use eqn 4.35 in exercises?

**2. Homework Equations**

**3. The Attempt at a Solution**