Physics - Advanced E&M: Ch 1 Math Concepts (29 of 55) Divergence of a Cylindrical Vector Field 1/2

In this video I will show how to take the divergence of a cylindrical vector field or a vector in cylindrical coordinates.

Next video in this series can be seen at:

[arunlal]

good explanations .. can u explain, two partial derivatives equations used for substitution ie d(unit row) / d(phi)=unit vector phi .. ( two equation in right top corner of the video) is formulated..

[evencloutier]

I don't understand why the dot product of the Del operator with the field vector gives 9 terms... shouldn't it be only three (Del term in direction of Rho with the component Rho of the vector, Phi with Phi and z with z)?
That is : (dr, dp, dz).(Ar, Ap, Az)= dr.Ar + dp.Ap + dz.Az
This is how the dot product usually work, is there a special rule for the Del operator?
why do we end up with: dr.Ar + dr.Ap +dr.Az + dp.Ar + dp.Ap + dp.Az + dz.Ap + dz.Ap + dz.Az ?

[PrashantKumar-zjeu]

sir, the explanation is awesome, but can u explain how those results written on the right size of the board came????

[jonathansum]

For people who get into this level, you will realize your math level is pretty much 6 grade.
The reason is, The more I get into certain fields, the more ignorant I feel in that certain field.

[kmajeremane]

the way you expand those brackets is giving me headaches, i dont know how you got some of those results