Recent content by fysiikka111

I am trying to compute the Fourier transform of a square pulse with MATLAB's FFT. Code: Fs=1000; %Sampling rate (Hz) T=1/Fs; %Sampling time interval P=10; %Period of pulse t=0:1/Fs:P/2; %Time axis N=length(t); x=rectpuls(t,P); %Pulse amplitude n=pow2(nextpow2(N)); %Number of frequency...

Thanks. How would you get rid of the factorial?

Homework Statement How to find for a Poisson distribution the number of successes for a given probability and mean. For example, for mean, \lambda, of 1, and a required probability of 0.01, what would the number of successes in the time interval be?Homework Equations...

Thanks a lot, that's a good method.

Right, thanks. If v = w^{3/2}, where w = \frac{2}{\mu_0}\left(\frac{dp}{dz}\frac{e^{3x}}{3}-C_1) , then with chain rule \frac{dv}{dx} = \frac{w^{1/2}e^{3x}}{\mu_{o}}\frac{dp}{dz} Hence \int\frac{dv}{dx}dx = w^{3/2} + C_{2}\rightarrow \int w^{1/2}dx =...

\begin{multline*}\frac{dp}{dz} = \mu_0 \frac{1}{e^{3x}} \frac{du}{dx} \frac{d}{dx} (\frac{du}{dx})\\ \frac{dp}{dz}x + C_{1} = \mu_0 \frac{1}{e^{3x}} u \frac{d}{dx}(\frac{du}{dx})\\ \frac{dp}{dz} \frac{x^{2}}{2} + C_{1}x + C_{2} = \mu_{o} \frac{1}{e^{3x}}u \frac{du}{dx}\\ u^{2}\mu_{o} =...

I've ended up with: u^{2}\mu_{o} = \frac{dp}{dz} \frac{x^{3}}{6}e^{3x} + C_{1}\frac{x^{2}}{2}e^{3x} + C_{2}xe^{3x} + C_{3} Is that right? Can I say that e3x=r3? Though I don't believe this is the way its meant to be done as it is unsolvable with three constants. Thanks a lot for your help.

Is this correct? \frac{dp}{dz} = \mu_{o} \frac{1}{e^{x}} \frac{du}{dx} \frac{d}{dx} (\frac{du}{dx}) = \frac{\mu_{o}}{de^{x}}du \frac{d}{dx}(\frac{du}{dx})

I see what I did wrong; I canceled both of the dr's when I integrated. \frac{dp}{dz}=\mu_{o} \frac{du}{de^{x}} \frac{1}{e^{x}} \frac{d}{de^{x}}(e^{x} \frac{du}{de^{x}}) How would you go about rearranging it now into a function of u? Don't need to show latex, just need a hint. Thanks.

Yes, its independent of r. May I ask which part of my first solution was incorrect? Thanks.

Thanks for replying. Do you mean if x=ln r, then subsitute r=ex into the equation?

Homework Statement \frac{dp}{dz}=\mu_{o}\frac{du}{dr}\frac{1}{r}\frac{d}{dr}(r \frac{du}{dr}) Homework Equations The Attempt at a Solution Multiply by r, and then integrate with respect to r to get: \frac{dp}{dz}\frac{r^{2}}{2}+C_{1}=\mu_{o}ur \frac{du}{dr} Divide by r and...

Thanks!

I did actually try that way also, with answer: \frac{F_{1}}{F_{2}}=\frac{F_{2}\pm\sqrt{1+F_{2}^2}}{-F_{1}\pm\sqrt{1+F_{1}^2}} I can't see how to simplify that either. But since F1 and F2 are constants, isn't it meaningless to take their roots? Thanks

Homework Statement Part of a larger problem. I know that F_{1}^2+2F_{1}F_{2}-F_{2}^2=0 where F_{1} and F_{2} are x and y components of a force. Hence \frac{F_{1}}{F_{2}}=1\pm\sqrt{2} I can't see how that step is done. Homework Equations The Attempt at a Solution...