Recent content by Painguy

Homework Statement Show that for any linear equation of the form \frac{dy}{dx} + P(x)y = 0 if y(x) is a soltuion, then for any constant C the function Cy(x) is also a solution Homework Equations The Attempt at a Solution (dy/dx) + P(x)y=0 ∫P(x)y=∫0 y=-C/P(x) C(dy/dx) +...

Homework Statement Homework Equations The Attempt at a Solution Here are my attempt. The top is when i tried using cylindrical coordinates. Instead of using dA=(cosθ i +sinθj)rdzdθ I used (cosθ i +sinθk)rdydθ since the cylinder is going along the y-axis rather than z. The...

How would that happen though? If a negative plate transfers its charge to the positive plate of the other capacitor then it just causes a chain reaction around the loop. I'm having a hard time seeing how everything will balance out.

Homework Statement Homework Equations Q=CThe Attempt at a Solution a) I want to say that since both have the same potentials then it is similar to a parallel circuit where the charges can differ on each capacitor. If i think of point A as an input and point B as an output then the potential...

Wouldn't that be generating level curves? I guess my terminology is bad. What i am asking is how do make f(x,y) into F(x,y,z)

Homework Statement given f(x,y)=9/(x+y) find a level surface. Homework Equations The Attempt at a Solution g(x,y,z)=f(x,y)-z=0? g(x,y,z)=9/(x+y) -z=0? That answer is wrong. Apparently i must have the following: g(x,y,z)=z(x+y)=9 How do I solve problems like these? Another...

Homework Statement I got an answer as you can see in both pictures, but apparently it is wrong. What did I do? Homework Equations The Attempt at a Solution In this picture I found the y components of the electric field at C. Since the bottom 2 are the same i just doubled one of...

Well the 1st part of the 1st question is asking that vector u be a unit vector which is why i had u.v=||v||. I can only think of 1 unit vectors that is in the same direction as v 1) u=2/√13i + 3/√13j I'm aware that there are infinitely many vectors that are parallel with v since I can...

Homework Statement 1)Give a unit vector a) in the same direction as v=2i +3j b)Perpendicular to v 2) a) Find a vector perpendicular to the plane z=2+3x-y b)Find a vector parallel to the plane Homework Equations The Attempt at a Solution 1) a) Method 1: u=v/||v|| so i...

Oh I see. Yeah I did do that division a bit earlier. That makes much more sense. Thanks very much for your help guys.

Oh right. That seems to work out. So a=-10. The two also seem to be parallel if a=0 since you would end up with -3j=6j but that isn't something that results from doing what you told me. Is that a trivial case i should just notice or is there an algebraic way of solving that? Thanks for your...

For what values of "a" are the vectors parallel Homework Statement v = 5a i -3 j w = a^2 i -6 j Homework Equations The Attempt at a Solution My first thought was too get the unit vectors of both and set them equal to each other and solve for a, but that got messy. (5a i-...

Homework Statement What are the sizes and directions of the currents through resistors (a) R2 and (b) R3 in Fig. 27-42, where each of the three resistances is 4.0 Ω? Homework Equations ΔV=IR The Attempt at a Solution Equations: 1) ΔVB2 -(i1)R1 -(i2)R2 -ΔVB1=0 5V - 4(i1)...

Did I evaluate my professors integral incorrectly?

I tried again. This time my professor's answer came out to be around 80.11. My answer however remained at 32, and wolfram alpha and my calculator give the same answer. here is my work.