Recent content by racnna

Hi guys..Here is a very short document on gateaux and frechet derivatives. http://www.scribd.com/doc/205731037/Optimization-of-Functionals any help will be appreciated

Homework Statement https://imagizer.imageshack.us/v2/622x210q90/833/sqaw.png I am having difficulty understanding the notation <h, f''(x0)h>

Aha! thanks so much gabba

woah easy there. I didnt mean to offend you. I just got worried because there were so many views and no replies so i thought there was a problem with the way the problem is worded. I think there's an infinite number of traction vectors?...but the rows of the Tensor should give you three...

uh oh...58 views and no replies? i am positive you experts have encountered stuff like this...there are much harder problems on this forum! if it helps, please IGNORE my post about relevant equations and just focus on the problem statement alright...and let me know if there's any confusion...

yes i got the same result for the unit vector. Thanks Ivy. Please see my other thread on the stress tensor. its a follow up to this question

Homework Statement http://img842.imageshack.us/img842/9577/stresstensor.png Homework Equations 'traction vectors' are just the rows of the stress tensor. that is, the first row of the stress tensor(the i-component of the tensor) is the first traction vector, second row is the second,etc...

hmm...it does work... ok i need to ask a follow up question but i'll create a new thread

Homework Statement ? How do i find a vector that has same angle with the three coordinate axes (x,y,z)? The Attempt at a Solution I immediately thought [1,1,1] would be it but it's not. I'm trying to find a plane whose normal vector forms the same angle with the three coordinate axes.

thanks! makes sense... im still trying to make sense of the meaning of ψ=constant. does it mean that if you take any small area element of the surface it is the same throughout the surface? is that a good way to interpret it?

zero?

i see..but again how am i supposed to differentiate a function when i don't know what the function is? should i just pick any function of x,y,z?

like this? grad(ψ) = \frac{\partial ψ}{\partial x} i + \frac{\partial ψ}{\partial y} j+ \frac{\partial ψ}{\partial z} k dχT= dx i + dy j +dz k are you saying grad(ψ) is 0 since ψ is constant?

so by saying that ψ is constant they're saying every point on this surface is the same distance fromt he origin...does that basically mean it HAS to be a sphere? or could it be some other surface?

oh i see...got it...yeah i was looking at it the wrong way