How can I calculate the electric field using the voltage and gradient?

[abcdefg10645]

I listed all my problem in the file below

I have figure out the V of that condition,

but I do not know how to use E= -delV at this eg.

 

[tiny-tim]

Hi abcdefg10645!

I listed all my problem in the file below

I have figure out the V of that condition,

but I do not know how to use E= -delV at this eg.

erm … there is no file …

but anyway it would be a lot easier for us if you would take the time to type out your question and your attempt for us (on the homework template, of course)