Question

What is the orientation of a surface?

Answer 1

use right hand rule

Answer 2

We went over this briefly in class and due to a sprained ankle, I was not there that day.

Answer 3

oh, ok, that is the best way to find it, but what exactly does it mean? I understand orientation of line integrals, but not surfaces.

Answer 4

Counter clock wise --> positive

clock wise --> negative

that's just the convention

Answer 5

so, same as line integrals then?

Answer 6

I think we use that in surface integral

Answer 7

http://en.wikipedia.org/wiki/File:Surface_vectors.png

For the right hand rule, I was always taught to pretend you were grabbing something like a bicycle handle. Your fingers sweep I into J, the direction of your thumb is K. http://en.wikipedia.org/wiki/Right_hand_rule

Answer 8

ok, thanks everyone! :)

Answer 9

hey, while i have you here, can you help with another question?

Answer 10

sure

Answer 11

cool, what is the relationship between surface integrals and area?

Answer 12

doesn't a surface integral calculate the area?

Answer 13

Well , if you take surface integral over sphere, you would get 4 pi r^2 , the surface area

Answer 14

true, so is that their overall relationship? you use the surface integral to calculate the area?

Answer 15

yes

Answer 16

ok, I thought it was more involved than that

Answer 17

it can be

Answer 18

ok, think along the lines of a multiple choice question

Answer 19

surface integral add up value of function over the surface. So if your function value is constant of 2 over the surface of sphere. The surface integral would be 8 Pi r^2

Answer 20

oh, kind of same thing as a line integral. ok

Answer 21

yep, but a lot more work

Answer 22

true that :)

Answer 23

when's your exam again?

Answer 24

Thursday

Answer 25

so if I am given a surface integral to solve, most likely I will be calculating the area?

Answer 26

yes

Answer 27

yeah, I'm taking all day tomorrow off to study

Answer 28

well after Thursday, no more calculus

Answer 29

thank you again for all of your help. we sort of flew through these last chapters

Answer 30

Don't worry about it.they won't go deep into these stuff in exam too

Answer 31

yay! well, at least for several weeks. I have MTHSC 208 in the spring. Not sure what that is, part 2 of Calc III? Calc IV? idk

Answer 32

math major?

Answer 33

yep, going for BA in Mathematical Sciences