Recent content by Pual Black

Ok i got it. Thank you for your help

I've uploaded my work as images. Sorry for not using LaTex but I am on mobile phone.

Homework Statement Hi sorry if the titel is wrong I want to know if i can write this ##a^2 + u^2 -2au= (a-u)^2 = (u-a)^2## I get different results when integrating ##x^{-\frac{3}{2}}## in the range ##(a-u)^2## to ##(a+u)^2##

Q1) the second expression. I think ##\phi## is a scalar and therefore it should not have an index. Right? Q2) yes i made a mistak. It should be ##dy=sin\theta sin\phi dr + r cos\theta sin\phi d\theta + r sin\theta cos\phi d\phi## Q3) so the final answer is Converge + Diverge = Diverge...

Homework Statement i have a few homework question and want to be sure if I have solved them right. Q1) Write ##\vec{\triangledown}\cdot\vec{\triangledown}\times\vec{A}## and ##\vec{\triangledown}\times\vec{\triangledown}\phi## in tensor index notation in ##R^3## Q2) the spherical coordinates...

The reason why i think the result is 2 because of a problem in Jackson Electrodynamic. I have now uploaded a pdf file and at page 1 you can see that the integral of dirac delta should be 2.

Since a=-1 is in the range of integral. The integral is equal one?

In L.H.S X must be equal a. Else dirac delta will be zero. R.H.S X=-1 Or a=-1 Maybe I didn't understand your question.

Homework Statement hi i have to find the result of ##\int_{0}^{\pi}[\delta(cos\theta-1)+ \delta(cos\theta+1)]sin\theta d\theta## Homework Equations i know from Dirac Delta Function that ##\int \delta(x-a)dx=1## if the region includes x=a and zero otherwise The Attempt at a Solution first i...

at l=0 the term vanishes. But what about the other values of l

Homework Statement Hi, The question is " Three point charges (q,−2q,q) are located in a straight line with separation a and with the middle charge (−2q) at the origin of a grounded conducting spherical shell of radius b ..." I have found a solution for this problem but there is one step that...

thank you again. Than my solution for spherical is also wrong. ( on page 4)

Thank you. You are great. I think i get it. I have uploaded an image with the solution. Sorry that i don't use Latex but I am on mobile phone right now. Is this correct?

Yes my problem is ##3.\triangledown\cdot r## in C.c.s. I don't know how to get 3 as result like R.c.s which is the correct answer. and my solution for the S.c.s I am not sure if its correct. Its seems wrong. I added the others so you can see how i solve the equations.

Homework Statement let ##\vec{r}## be a vector from origin to the point (x,y,z) and let ##{\vec{r}\,}'## be a vector from the origin to the point (x',y',z'). Evaluate the following expressions ##1. \triangledown r ## ##2.\triangledown\frac{1}{r}## ##3.\triangledown\cdot r##...