Recent content by jerzey101

Ok I'm starting to get it. Thank sharks!

Thanks LCKurtz, that is similar to what we were doing in my class. I was getting confused by what sharks was doing.

Meaning integrate it over the paraboloid?

so -8x + 12y - 3 all over [itex]\sqrt{4x2+4y2+1}[\itex] I'm sorry, I am so lost with this one. And I am doing battle with the formatting. I don't get why it's not working

Thanks! I think I figured it all out now. Thanks again.

I'm just not sure what to put for the r limits. I know it is 0 to the circle x2+y2=4. So is it just 0 to 2?

So (2x,2y,1) / sqrt(4x2+4y2+1) how do you go about simplifying this?

Homework Statement Use polar coordinates to evaluate: ∫sqrt(2)0 ∫sqrt(4-y2)y 1/(1+x2+y2) dxdy Homework Equations The Attempt at a Solution I graphed it and I see r is the part of the elipse sqrt(4-y2) and goes from 0 to ∏/4. I'm not sure how to make the bounds for r or how to...

Homework Statement Verify Stokes' Theorem for F(x,y,z)=(3y,4z,-6x) where S is part of the paraboloid z=9-x2-y2 that lies above the xy-plane, oriented upward. Homework Equations Stokes' Theorem is ∫F*ds=∫∫scurl(F)*ds Where curl(F)=∇*F The Attempt at a Solution I got...

my answer should be negative, i just forgot to type the -. I see about just using the volume formulas. I'm just studying for my calc class so I wanted to learn the integral way because that's what I will have to do on the exam. Thanks again.

Thank you sharks. I really appreciate it. ∫∫∫52r drdθdz = 1248∏ which is the correct answer. How do you know right off the bat to use the divergence theorem? Just from practice?

ooo ok. Thanks a lot!

I believe I got it. so div(F)=0+1+0=1 using spherical coordinates [SIZE="5"]∫2∏0∫∏0∫10p2sin∅ dpd∅dθ which I got to equal 4/3∏ That look correct?

Homework Statement The temperatur at the point (x,y,z) in a substance with conductivity K=6.5 is u(x,y,z)=2y2+2z2. Find the rate of heat flow inward across the cylindrical surface y2+z2=6, 0≤x≤4. Homework Equations F=-k∇u -k∫∫s∇u*ds The Attempt at a Solution So F=-6.5(0,4y,4z) I...

Homework Statement Compute the flux of the vector field F(x,y,z)=(z,y,x) across the unit sphere x2+y2+z2=1 Homework Equations I believe the forumla is ∫∫D F(I(u,v))*n dudv I do not know how to do the parameterization of the sphere and then I keep getting messed up with the normal vector.*...