# Recent content by november1992

1. ### Calculating Triple Integrals in Mathematica

This problem was given to me by my instructor.
2. ### Calculating Triple Integrals in Mathematica

Homework Statement Evaluate ∫∫∫\sqrt{x^{2} + y^{2}} dA where R is the region bounded by the paraboloid y=x^2+z^2 and the plane y=4 Homework Equations I believe this is a problem where cylindrical coordinates would be useful 0 ≤ z ≤ \sqrt{4-x^2} 0 ≤ r ≤ 2 ( I think this is wrong). 0 ≤ θ ≤...
3. ### How to calculate curvature of a vector in Mathematica.

I can't believe I overlooked that. I also removed the parentheses. Now I'm getting 26.89. Thanks for the help
4. ### How to calculate curvature of a vector in Mathematica.

I tried it 3 different ways and I still get 20.39 http://i.imgur.com/mQW6TaO.png http://i.imgur.com/DmTseJc.png http://i.imgur.com/QKfTfoW.png
5. ### How to calculate curvature of a vector in Mathematica.

I'm not getting a number. http://i.imgur.com/mQ4Pfac.png I'm guessing I have incorrect syntax. Edit: I realized i didn't capitalize the 'p' in Pi. now I"m getting 13k though I got 20.39
6. ### How to calculate curvature of a vector in Mathematica.

From my textbook. I scanned the page I found it from. http://i.imgur.com/AivojRL.jpg
7. ### How to calculate curvature of a vector in Mathematica.

Okay, thanks. I have one last question. How can I use the inte\frac{}{}rval <0,4pi> in this equation? I'm just a little confused about why this formula, k = |\frac{r(t)' X r(t)''}{r(t)'^3}| gives a different answer to the formula you posted
8. ### How to calculate curvature of a vector in Mathematica.

Haha, I actually managed to plot it, but I thought it was wrong because I wasn't expecting a huge wave. I was also told to calculate the length of the curvature. Do you think this would be an acceptable answer? http://i.imgur.com/HHYzFy7.png Is there a way to simplify this expression?
9. ### How to calculate curvature of a vector in Mathematica.

It doesn't seem to make a difference. http://i.imgur.com/woWlabm.png http://i.imgur.com/ptUZcVG.png
10. ### How to calculate curvature of a vector in Mathematica.

Homework Statement r(t)={(4+cos20t) cost,+(4+cos20t) sint,+0.4sin20t} Calculate the curvature of r[t] for 0≤t≤4pi Homework Equations k = | r' x r'' | / | r' |^3 The Attempt at a Solution r[t_]:={4+Cos[20t]*Cos[t],4+Cos[20t]*Sin[t],0.4Sin[20t]} k[t_]:=Norm[Cross[r',r'']]/Norm[r']^3...
11. ### Using Node-Voltage method in the phasor domain

I was wondering if there is an easier way to solve circuits using matrix inversion if I have complex numbers. So far I've been doing them by hand with 2x2 matrices. It isn't hard, but it takes a while. I have a test coming up in about a week which will have 10 questions that have to be solved in...
12. ### Two parallel mirrors are separated by a certain distance

Your explanation confused me, but I got the answer right answer. I'm not sure why though. I doubled the distance from the object to the first mirror and added that to the distance of the second image from the first mirror.

What is dn?
14. ### Two parallel mirrors are separated by a certain distance

Homework Statement Two parallel mirrors are separated by a distance of d = 4 meter. A point object is placed at a position a = 0.4 meter from the mirror 1. How deep is the second image of the object in the mirror 1? How deep is the third image of the object in the mirror 1...
15. ### Laplace transform of the dirac delta function

I don't see that formula in my textbook. When I plug in the numbers I get: \frac{2}{s^3} + \frac{e^-s}{s} This is what I did to get my first answer. L[t^2 - t^2 δ(t-1))] \frac{2}{s^3} + \frac{d}{ds} (\frac{d}{ds} (\frac{e^(-s)}{s}) \frac{2}{s^3} +\frac{d}{ds} (\frac{e^-s...