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1. ### Nabla Operator Question

=\frac{-r\hat{r}}{r^{3}} ?? so it's the negative r unit vector pointing in the r direction.. over r cubed.. right? =( I seem to have a huge knowledge hole about vectors
2. ### Nabla Operator Question

I don't understand the differences between: \vec{r},\hat{r} and r! =(
3. ### Nabla Operator Question

I'm thinking hard but I'm not sure.. I'm thinking something along the lines of.. the x-component of \hat{r}.. the y-component. or something? >_<
4. ### Nabla Operator Question

r^{2} = x^{2}+y^{2}+z^{2}? - \hat{r} = -x \hat{e_1}-y\hat{e_2}-z \hat{e_3}? So final answer: \frac{-\hat{r}}{r^{5/2}} ?
5. ### Nabla Operator Question

Is this better? I can't figure out how to simplify it further.
6. ### Nabla Operator Question

Does my solution look correct to you guys? Homework Statement Calculate: \nabla \varphi (r) If: \varphi (r) = \frac{1}{4\pi\epsilon_{0}}\frac{1}{r} with: r = \sqrt{x^{2}+y^{2}+z^{2}} Homework Equations n/a The Attempt at a Solution
7. ### Product rule with 3 variables

Thankyou very much. Yes, I was trying to find y' in terms of the other stuff. Previously, I had only learned the product rule for two variables.. like u'.v + u.v'.
8. ### Product rule with 3 variables

hey there, At the moment at school I'm doing Implicit Differentiation. If i had for Instence 2y'yx + 6x = 0 how can I use the product rule on the first step when there are 3 variables? Cheers- Andy