# Search results for query: *

1. ### Difficult exponential equation

Unfortunately, due to the properties of exponentials, I don't think I can take the t out. If the exponents of the exponential were sums instead of products, the problem would be much easier and would allow me to factor out an e^t. But I'm not sure how to isolate the t in this specific equation.
2. ### Difficult exponential equation

1. I need to solve the following exponential equation for t. \frac{1}{20} =0.5 e^{-0.877t} - 0.05 e ^{-9.123t}
3. ### Fortran Fortran DO command

nevermind, figured it out. I did not define "i" as a variable in my list of integers
4. ### Fortran Fortran DO command

I am working with visual Fortran (f90 I believe) I have the following program and it says that I have 2 errors. I have narrowed it down to having something to do with my loop statement in bold. Is there something wrong that I'm not getting? program exercise1 implicit none...
5. ### Centroid of cylindrical cone

Thank you. I was essentially doing the right thing on my first try before I changed everything, but I made an algebra mistake when trying to use cylindrical coordinates. Thanks for the short cut ... less room for stupid mistakes.
6. ### Centroid of cylindrical cone

Homework Statement Determine the centroid of volume for a right circular cone with base diameter of 100mm and an altitude of 200mm. Homework Equations I know that if the my xy-plane is parallel to the base of the cylindrical cone then the x and y coordinates of the centroid must be...
7. ### Comp Sci Fortran Programming

I know that I can go to Build in the toolbar and click on "Compile invert.f90". And this comes up in the bottom window: --------------------Configuration: myproj - Win32 Debug-------------------- Compiling Fortran... C:\Program Files\Microsoft Visual Studio\MyProjects\myproj\invert.f90...
8. ### Comp Sci Fortran Programming

I downloaded 'Compaque Visual Fortran 6' This came with: WinDiff, VF reporter, Spy++, Process Viewer, OLE-COM object viewer, Fortran Module Wizard, Fortran Command Prompt, Error Lookup, Developer Studio, Dependency Walker. I guess my question is how to run a program once it is written. I...
9. ### Comp Sci Fortran Programming

I feel very silly for asking this but I have just downloaded Fortran 90 and am trying to figure out how to open the command window. I am used to using MATLAB which automatically opens a command window when you open the program. I have the option of opening the developer studio or the command...
10. ### Integral involving sine and root

Thanks. That's exactly what I needed.
11. ### Integral involving sine and root

Homework Statement \int_0^{\infty} sin(ax) / sqrt(x) dx Homework Equations The Attempt at a Solution I thought of using integration by parts, but that gets me nowhere. I'm not sure how to go about this problem.
12. ### Difficult integral involving exponential

Homework Statement I'm trying to verify the Fourier transform but am getting stuck on the integration. Here is the pair: f(x) = e^{-ax^2} \hat{f}(k) = \frac{1}{\sqrt{2a}}e^{-k^2/4a} a>0 Homework Equations I know that \hat{f}(k)=\int_{-\infty}^{\infty}f(x)e^{ikx}dx The Attempt at a...
13. ### Dirac delta function proof

delta tends to zero very quickly when x does not equal a (which is zero in this case) by definition of the generalized function . If that's right, then I think I get it. Thank you for your help.
14. ### Dirac delta function proof

thank you, i did leave out a minus sign. I will correct that above. Also, I think I was trying to make things more complicated than they actually are. But why does the first term when doing integration by parts go to zero? \boxed{[f(x)\delta(x)]_{-\infty}^{\infty}} - \int_{-\infty}^{\infty}...
15. ### Dirac delta function proof

1. The problem statement Show that: \int_{-\infty}^{\infty} f(x) \delta^{(n)}(x-a) dx = (-1)^n f^{(n)}(a) The Attempt at a Solution I am trying to understand how to prove: \int_{-\infty}^{\infty} f(x) \delta '(x) dx =- f'(x) I know that we need to use integration by parts, but I'm...