Good morning Sir, please can you explain slide 21, I don’t understand how we arrived at the equation with the dot product of E1 with e1 and e2, also in slide 23

What you do in these kinds of situations is to work backward – from answer to question. Since you know the magnitude of the vectors and the angles between them, ask yourself, what is the definition of the dot product? If you put that definition into action and compute based on the magnitudes and angles that are supplied, the answer jumps out. What I will agree with you to be difficult initially is to move forward; moving backwards is quite easy. After a while, with experience, you find that moving forward is equally easy.

Good morning sir. This is not a question butt a comment. I realized that the knowledge and understanding od the Vector Triple product and Scalar triple product will melt the confusion that arises with many vector operations in the text for the course away. Thank you sir

{If a free index is missing in a term, there is an error.}
and there are some equations have seen without a free index
eg
eijk Tj ei from solved problem 1.7

Good morning Sir, please can you explain slide 21, I don’t understand how we arrived at the equation with the dot product of E1 with e1 and e2, also in slide 23

What you do in these kinds of situations is to work backward – from answer to question. Since you know the magnitude of the vectors and the angles between them, ask yourself, what is the definition of the dot product? If you put that definition into action and compute based on the magnitudes and angles that are supplied, the answer jumps out. What I will agree with you to be difficult initially is to move forward; moving backwards is quite easy. After a while, with experience, you find that moving forward is equally easy.

Good morning sir. This is not a question butt a comment. I realized that the knowledge and understanding od the Vector Triple product and Scalar triple product will melt the confusion that arises with many vector operations in the text for the course away. Thank you sir

Good day sir,

according to tell tale sign 2

{If a free index is missing in a term, there is an error.}

and there are some equations have seen without a free index

eg

eijk Tj ei from solved problem 1.7

Good evening, sir. I wanted to ask, does the spherical tensor have any relation to a spherical 3d space or to spherical coordinates ?

No relationship at all.