Recent content by jimbo71

i don't know where to start!

Homework Statement a solid in the first octant is bounded by the planes y=0 and z=0 and by the surfaces z=4-x^2 and x=y^2. its density function =kxy, k is a constant. find the mass of the solid and the center of mass Homework Equations My= double integral of D[x*kxy]dA Mx=double...

Homework Statement the region between the planes x+y+2z=2 and 2x+2y+z=4 in the first octant Homework Equations triple integral of region R dzdxdy The Attempt at a Solution I need a lot of help starting this problem. I have no idea what to do. Please help me!

Homework Statement the region in the first octant bounded by the coordinate planes and the planes x+z=1, y+2x=2 Homework Equations triple integral or region R dzdxdy? The Attempt at a Solution i need a lot of help for this problem

converted the cartesian equations to polar and used the 1/area*double integral of region R [z]rdrdpheta. I am having much difficulty integrating r*sqrt(a^2-r^2). i tried a trig substitution but don't know how to finish from there. please help me!

Homework Statement find the anverage heigh of z=sqrt(a^2-x^2-y^2) constricted by the cone x^2+y^2<=a^2 in the xy plane Homework Equations Average Height =(1/area)*double integral of region of [z]drdpheta The Attempt at a Solution I really have no idea how to solve this problem can...

Homework Statement convert line one to polar integral and then evaluate see problems 16 attachement Homework Equations r^2=y^2+x^2 The Attempt at a Solution I changed to polar and evaluated the double integral but I come up with an answer of negative pi which seems odd since it...

Homework Statement convert double integral from line one to polar integral and then evaluate see problem 12 attachment Homework Equations y=rsinx x=rcosx r^2=x^2+y^2 The Attempt at a Solution see problem 12 attachment I calculate a area of zero. are my limits wrong and if...

please help asap !

any ideas how to calculate b field with such an experiment?

Homework Statement x^2+y^2=r^2 y-rcos(pheta) find (partialy/partialr)subscribt phetal, find (partialy/partialpheta)subscribtx, and find (partialy/partial)subsribt pehta Homework Equations im not sure how to write this partial in chain rule form. i think the first one...

Homework Statement During a lab we used a 570turn solenoid powered by a current of 5amp. For the last part of the experiment we were to take several measurements of the field strength across the cross-section of the solenoid. So we moved the field sensor around inside the solenoid and made...

Help Me It is very important I complete this problem. How do i solve the 4 equations?

Homework Statement Find the maximum values of f(x,y,z)=xy+xz+yz-4xyz subject to the constraints x+y+z=1 and x,y,z>or equal 0. Homework Equations The Attempt at a Solution see attachment I found fgrad and ggrad and set fgrad equal to lambda*ggrad and used x+y+z=1 for my system of...

i need help asap