Surface Integral - What is the process from the beginning to the end?

I have been studying it, but I am unable to understand the "between" steps the teacher does. (He skips A LOT of math and does not show the methods used to solve)

Look at attachment below~

Question

Surface Integral - What is the process from the beginning to the end?

I have been studying it, but I am unable to understand the "between" steps the teacher does. (He skips A LOT of math and does not show the methods used to solve)

Look at attachment below~

anonymous · Answer

attachment

anonymous · Answer

integral(xj dS) is what we need to calculate (surface integral)

dan815 · Answer

confused what the question actually is

dan815 · Answer

okay lets start here G(x,y) = 1+y^2, so this is your surface, now what do u wanna do with this?

dan815 · Answer

are you there? this notation u are using doesnt completel make sense to me, do u wanna do liek a dot product integral thing?

dan815 · Answer

integral xj dot n^ ds?

dan815 · Answer

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