(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Hi...

How can one be sure that

[tex]

d\textbf{E}=\frac{kdQ}{r^2}(\cos\theta \textbf{i} + \sin\theta \textbf{j})

[/tex]

Is true for a small charge dQ

Is there some derivation for this?

2. Relevant equations

3. The attempt at a solution

I have a problem for homework that uses this equation... I know how to solve the problem, but I feel like I should know how this equation works since I dont want to just mindlessly plug in information... Thanks.

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# Homework Help: Definition of electric field dE due to a small charge dQ

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