Recent content by Numbnut247

i know if f is differentiable at a point x, there exists a linear map and a remainder function r which is continuous at 0 and r(0)=0. i know if f is linear, then it's multiplication by a matrix and the matrix is the derivative of f but there's the v transpose which confuses me...

uh... we never proved any differentiation rules yet:S but i think you are referring to the product rule? but i don't know how they work in R^n or with linear maps. I'm really lost actually... haha. I don't get how i can somehow use the 1x1 matrix thing, either...

Homework Statement Suppose A is a real nxn matrix and f: R^n --> R is definted by f(v)=v^tAv (where v^t denotes the transpose of v). Prove that the derivative of f satisfies (f'(v))(w) = v^t (A+A^t)w Homework Equations The Attempt at a Solution I'm kinda lost here and I really...

Got it, thanks a lot guys

Hey guys, I have a few questions: 1. There are 35 desks in a classroom. In how many ways can the teacher configure a seating plan for a class of 30 students? I'm not sure if order matters (35P30 or 35C30). 2. Sixteen people attend a meeting. Each person greets everyone with a single...

Sweet:smile: Thanks for all your help:smile:

I'm thinking that the -10uC sphere's charge will cancel out the other sphere's charge of +6uC. So you will have a -4uC sphere and a neutral sphere. Because they touched, -2uC charge will travel to the neutral sphere. In the end, both spheres will have -2uC as their charges; as a result, when...

Kinda off-topic (I didn't want to make a new thread), but do you guys know what happens when a -10uC charged sphere touches a +6uC charged sphere? Would the two spheres turn to -8uC and + 4uC. u = micro The original question: Two small identical spheres contain excess charges of -10uC and...

Thank you. Now the only thing I am still confused about is if I draw only 4 electric field lines (1 for each + charge)?

This is all I know about the questions: Draw electric fields for the following: A hollow metal sphere with a + charge http://img340.imageshack.us/img340/9207/untitled2oe.png

I'm taking Physics 12 in BC, Canada. So would this be correct? http://img58.imageshack.us/img58/1827/untitled5ja.png

Would it be one of those: http://img450.imageshack.us/img450/8461/untitled5ib1.png What I am confused about are: 1. Are there only 4 electric field lines (cause there are only 4 charges) (I think there are more than 4 lines, but I am not 100 percent sure) 2. Are there electric field...

Hey guys, how do I draw electric fields for this? A hollow metal sphere with a + charge http://img340.imageshack.us/img340/9207/untitled2oe.png Can the electric field be outside of the metal sphere or does it have to be only in the sphere?

Hey guys, how can I tell whether a reaction is a redox reaction? For example: 2H2O --> 2H2 + O2

Thank you so much :smile: :smile: :smile: I have one last question (PROMISE): A person is on a horizontal rotating platform at a distance of 4.3m from the its centre. This person experiences a centripetal acceleration of 5.6m/s^2. What centripetal acceleration is experienced by another...