Question

Please help me with questions: 5, 6, 10, 11 and 12:

Answer 1

@lgbasallote

Answer 2

@A.Avinash_Goutham @ali110 @apoorvk

Answer 3

@mahmit2012

Answer 4

lol why tag me...tag the greater ones :p

Answer 5

you are one of the greater ones :P

Answer 6

http://openstudy.com/study?login#/updates/502624f2e4b0906b1afe4628
check that link for part 10 & for curl

Answer 7

thnx ali :)

Answer 8

question 5 \[\nabla.(n r^{n-2} (\vec a.\vec r)\vec r+r^n \ \vec a)=0 \]\[\nabla.(n r^{n-2} (\vec a.\vec r)\vec r)+\nabla.(r^n \ \vec a)=0 \]-------------------------------------
Using the Prperty : if \(\rho\) is a scalar valued function and \(F\) is a vector field, then
\[\nabla.(\rho F)=F.\nabla\rho+\rho \nabla .F\]and part \(iv\) from question 4
--------------------------------------------

i just wanna simplify \(\nabla.(n r^{n-2} (\vec a.\vec r)\vec r)\) u do the rest :) \[\nabla.(n r^{n-2} (\vec a.\vec r)\vec r)=n((\vec a.\vec r)\vec r).\nabla r^{n-2}+nr^{n-2} \nabla .((\vec a.\vec r)\vec r)\\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ =n(n-2)r^{n-4}(\vec a.\vec r) (\vec r.\vec r)+4nr^{n-2} (\vec a.\vec r)\\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ =n(n-2)r^{n-2}(\vec a.\vec r)+4nr^{n-2} (\vec a.\vec r)\]

Answer 9

hey guys.... please help me with question 6, i've tried so many different methods to solve it, and i dont seem to get anywhere close to an answer

Answer 10

thanks @Hero

Answer 11

@TuringTest ?

Answer 12

yikes, I'm trying to look up something that could help in my vector calc book, but this is definitely stretching my limits...

Answer 13

awwh thanks @TuringTest which book do you use? i use Vector Calculus by Shanti Narayan

Answer 14

hahaha

Answer 15

I have a Leithold calc book actually, it's not just vector calc, so it may not be detailed enough
\[r.a\]is the dot product, right? I only ask because it seems strange to me that they put the dot so low in the problems

Answer 16

yes its da dot product

Answer 17

I think this is why I need to do the OCW multivariable course all the way through... I don't think I can help :/

Answer 18

oh, its ok, but thanks for trying :) @TuringTest

Answer 19

I don't know if this is right, but I'm getting ANY function for 6. Why? Using the Jacobi identity allows us to prove that (a ^ r)^r is zero.

Answer 20

i wanna call someone to help

Answer 21

@rezas

Answer 22

I will be back Ka

Answer 23

ok

Answer 24

heyy guys i need help with the very last part of question 10 where it says verify the the formula by calculating both sides..... ive done every other question, plz try question 10, Thankyou all for your help, i really appreciate it