# Thread: surface A-calculus for upcomingexam

1. ## surface A-calculus for upcomingexam

Hi,
I am having issues here.thanks
Determine surface A such that
∫∫s(∇xF).nds =∫∫A(∇xF).kda
explain why inequality holds

2. ## Re: surface A-calculus for upcomingexam

Hey n22.

Consider a flat surface.

3. ## Re: surface A-calculus for upcomingexam

Originally Posted by n22
Hi,
I am having issues here.thanks
Determine surface A such that
∫∫s(∇xF).nds =∫∫A(∇xF).kda
explain why inequality holds
I am confused as to what you mean here. Is "n" the unit normal to surface S and "k" the unit normal to surface A?

Apparently you are to find a surface, "A", so that the integral of $\displaystyle \nabla\times F$ over A is the same as the integral over S? What is "S"? Wouldn't it be simplest to take A= S?

And, since you have "=" between those two integrals, what does "explain why inequality holds" mean?

4. ## Re: surface A-calculus for upcomingexam

Originally Posted by HallsofIvy
I am confused as to what you mean here. Is "n" the unit normal to surface S and "k" the unit normal to surface A?

Apparently you are to find a surface, "A", so that the integral of $\displaystyle \nabla\times F$ over A is the same as the integral over S? What is "S"? Wouldn't it be simplest to take A= S?

And, since you have "=" between those two integrals, what does "explain why inequality holds" mean?
yes.you are correct theres nothing to be confused about.
Am I just proving that LHS=RHS?