Recent content by Xinthose

True, but that new CAS is awesome. I did the math by hand eventually, after many, many google searches on the right steps to take

yup, thank you LCKurtz. That was the obvious answer. Now that I have a TI-nspire CAS, I can just type it in and it comes out

I still don't see how they did it, sorry.

I realize that Δ(s) is the cross product of the matrix on the left, but how did the solutions manual get the matrix on the far right multiplied by R_1(s) and R_2(s)? I need those matrix values to do the rest of the problem. Any help is appreciated, thank you.

Basically I think convolution is the summation of signal functions from one minimum value to a maximum value: (0 to 2 ) Ʃ v[n - i ] ⇔ v[n] + v[n-1] + v[n-2] . The brackets mean that we are using discrete time I think.

You failed me Physics Forums; here is the scanned answer from my professor's solution set given to us after the test; I hope that this will help someone else out there; Make of it what you will; his handwriting is kind of hard to read...

Alright, but you eventually get E = Q / (4 * pi * ε * a * b) ; so how would you get a ratio from that from b to a ?

I do know, from Wikipedia, that concerning concentric spheres, Cap = 4 (pi) ε / ( (1 /a) - (1/b) )

Homework Statement It's desired to build a capacitor which has two concentric spheres separated by a dielectric of high permittivity, low loss, and high dielectric strength. Calculate the ratio of sphere b's radius to sphere a's radius which produces the lowest electric field between the...