Mathematica Definition and 1000 Threads

Every time I try to do a simple definite integral simbolically such as: Integrate[R/P - c1/(T^2), {P,P1,P2}] it takes about 2 minutes then gives a long conditional expression. Basically it assumes that P1 and P2 are general numbers with complex parts and negative and such. HOW do I tell...

Hello, I am new to mathematica, and I am having trouble using the solve/nsolve to solve my system of three equations. Attached is my code so far. Any help would be greatly appreciated. It gets stuck in the loop section of the code. I have also pasted the code below. Thanks! Alicia...

I am dealing with a set of data where I have values C(x,t) for a discrete set of x and t values. Say: x={1,5} t={1,3,7} C={{C(1,1),C(1,3),C(1,7)},{C(5,1),C(5,3),C(5,7)}}. How do I combine this to a list that looks like...

Hi all. My professor gave us some integrals that Mathematica can't do, and we have to teach Mathematica how to do them. I got the first two, but I'm stuck with the u substitutions for these six. I know that I am supposed to make an attempt at a solution, but I've tried several different u...

After conducting my experimental work I will have a number of sets of data. It is easy to use Mathematica to find a fit of just one set, but I would like to fit all sets at once as they are too many to do them all ate once. They will all be fitted by the same function say y=ax+b, every set...

I just need to know how can Mathematica recognize e^{-i\theta} as the eulers identity. This is, e^{-i\theta} = cos \theta + sin \theta . When i plot a function like e^{i\theta}, nothings appear in the graph. Help is appreciated.

Is it possible to get either one to display the less factored form of an expression? what I am doing is multiplying matrices together for geometrical optics but my answers keep coming out really ugly. For example I have d-d\left(\frac{2d}{r}-1\right) I don't think a person would ever write...

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...

Hello all, It's quite a mouthful but I need help writing a function that will behave as follows: 1.if called with an argument which is an integer, it will return the absolute value of the input 2. if called with a real argument, it will return the number rounded to the nearest...

Greetings, I recently discovered Mathematica's Format function, and it has been of great use to me. However, there is one thing that I want to use it to do, that I have yet to be able to. I could do this easily, though, if there is some Mathematica function that works as follows... If I put a...

Hi all. Is there a way to plot both functions and coordinates/points on the same graph in Mathematica? The various functions for plotting each seem very incompatible. I would like to compare a probability function to Monte-Carlo-method simulation results. Also, out of curiosity, do...

I'm trying to find the integration of my function f[x] from 1 to 4 using the indefinite integral and inserting limits using rules. I am not sure how to insert the limits with rules, have been playing about with the following Integrate[f[x], x] /. x -> {1 >= x <= 4} which ain't working, any...

I wonder which one is more accurate when solving differential equations?

Why do I keep getting output that looks like this when I use Mathematica? $$\frac{2 b k |a+b v| (2 a+b v+b v \cos (t)) \sin ^2\left(\frac{t}{2}\right)}{(a+b v)^2 \sqrt{\left(\frac{1}{\sqrt{4 a^2 k^2 \sin ^4\left(\frac{t}{2}\right)+d^2 (a+b v)^2 \sin ^2(t)}}\right)^* \sqrt{4 a^2 k^2 \sin...

How can I extract time data from a system 2nd order ODEs in Mathematica?

I used mathematica to solve a restricted 3 body problem and was able to export my position data at different time intervals. How can I find my velocity at that final location?

Can someone identity what the issue here is before I throw my computer out the window. By the way, this just worked 10mins ago. I restarted Mathematica and my computer but it now insist z isn't an equation. ClearAll["Global`*"]; me = 5.974*10^(24); mm = 7.348*10^(22); G = 6.67259*10^(-20)...

I have a LARGE function that I must integrate over 2 variables, {x,y} both from 0 to 1. The Function looks like : F[x_,y_] = A[q] G[x,y] + B[q] G2[x,y] + (...) Where (...) MAY be 100's of terms long, if not thousands. But the fact is each term is separable, in SOME way to a function of...

Homework Statement Hey all, this is for a laboratory. I need to determine the fractal basin boundaries for a magnetic pendulum swinging chaotically about 3 other magnets underneath. I was able to plot a single path for the pendulum in Mathematica, but now I need to expand my code to...

What are the rules of analytical – not numerical (matrix) entry of bra-ket convertion – operations on bra-ket, in particular – tensor product ? For example – how in analytical form to do this: U|\Psi\rangle where: U=I\otimesI I=|0\rangle\langle0|+|1\rangle\langle1|...

First of all, this might give seasoned Mathematica users some serious eye sores cause I'm a newb at this xD f[x_] := (1^-9) (Exp[38.629 x] - 1); data = Table[if[[f[x], {x, -5, 5, 0.01}] > 0.005, 0.005, f[x]]]; ListPlot [data, DataRange -> {-5, 5}, Joined -> True, PlotRange -> {0, 0.01}...

Hello, I am using mathematica 9 and having some problems with a particular expression, but when I tried it on mathematica 8 it worked perfectly. My expression is: NDSolve[{D[T[n,z], n]+i 2 D[T[n,z], {z,2}]+z^2 T[n,z]==0, T[0,z]==1, Derivative[0,1][T][n,5]==0, Derivative[0,1][T][n,0]==0}, T...

Simple Matrices proof using Mathematica help! Homework Statement Hey guys, I'm trying to prove that (AB)-1 = B-1 A-1 and also the one that looks the same but is with transpose of the matrices making A and B arbitrary 3x3 matrices. I made A = {{a_1,a_2,a_3}...} B =...

If anyone on here uses Mathematica maybe you could help me with an issue I am having with computing the following: Solving for x in: Sinc[x] > (1/1.01) I am looking only at the positive values and not making any headway with the Solve or NSolve commands. I should also mention that this...

Homework Statement Hello. My problem is that I need to learn how to use computer software this semester. My teacher said, go and figure out how to use any computer software you like to make graphs. I have Mathematica but I am not proficient in using it, could somebody please help me with...

(c (qz + (-1 + q) (-1 + (1 + qz)^0.5)))/(h q^2 (1 + z)^2) = d, And to solve for q New to the programme, thanks a lot !

Can anyone tell me what is the problem with this Mathematica code? Nmax = 10; Mmax = 10; A = 4/Pi^2*Integrate[x*Sin[n*x]*Sin[m*y], {x, 0, Pi}, {y, 0, Pi}]; B = 4/Pi^2*Integrate[Sin[n*x]*Sin[m*y], {x, 0, Pi}, {y, 0, Pi}]; u[x_, y_, t_] = Sum[Sin[n*x]* Sin[m*y] (A*Cos[(n^2 + m^2)*t] +...

Hi there I was sent a .nb file with calculations already done for me, for various inputs. I was wondering how I can edit those inputs, keeping the rest of the calculations the same, to find out what the result would be? (see attached file for example)

Hi I decided to purchase mathematica, however it appears this is a much more complicated affair than I had imagined. I will mainly be using it for differential equations (nonlinear, nonhomogenous and coupled, what have you) to help with physics. Could someone clear up some questions I have...

How do I use the Bessel Function at different orders to approximate the sine function? I am plotting $\sin\pi x$ against the BesselJ function. However, from the example I saw in class, as I increase the number of terms, the $(0,1)$ coordinate is pulled down to (0,0). This isn't happening for...

Hi, So here's my latest problem as I get to grips with Mathematica. I will give a simpler version of the one I am actually doing. I started with a closed set of differential equations. Consider the following equations a'(t)=P*b(t) b'(t)=P^{2}*a(t) with known initial conditions and P is a...

Hi, all! I have trouble by using Mathemtica to solve the following problem as shown on the attachment. You see that the two recursive relations depend one another. I plan to write a "For" loop to evaluate E, instead of using Rsolve (a build-in function in Mathematica), however, I am very new...

Hello. I'm trying to consider a matrix A and looking at Ak and (Ak)TAk, where T is the usual transpose. This is no big deal. But I'd rather not look at them one at a time--I want to consider some powers k from 1 through as high as I want them. When I try Table[MatrixPower[A...

f[r_][x_] := 1 + r*x + x^2; A = Table[ cps[r_] = x /. Quiet[Solve[f[r][x] == 0, x], Solve::ratnz], {r, -5, 5, 0.01}]; I want to then tell mathematica to check the derivative of f with each value from the table, plot the values, but make the lines where there derivative in less than 0...

Good evening, I am currently trying to use Mathematica to find the symbolic solutions to a set of complex linear equations. I have never used Mathematica for such a task before and am finding it quite difficult. Let me state the problem...

How can I tell Mathematica to expand cos^5 t? The command expand doesn't do it.

I have a set of data points \{\{x_1, y_1\}, \{x_2, y_2\} ... \} each with an uncertainty \{\{dx_1, dy_1,\}, \{dx_2, dy_2\} ...\}. Is there any way of fitting a nonlinear model to the data that incorporates the uncertainties on both x and y? I know that you can use the Weights command to...

Hello, I need some assistance with Mathematica. I'm very new to the software, and am not very familiar with the programming language. I guess I'm a little bit lost as to where to go after defining my function. I'm not sure how to apply constraints, or really how to jump in and tackle this...

Homework Statement evaluate $$\int_0^1\frac{Ln(x)}{1+x}\,dx$$ Homework Equations I know the way to solve most improper integrals; replacing 0 or the bound causing the issue with a variable and have the limit of the integral as the variable goes to infinity. My question is using...

Hello, I have a system of DE involving two variables depending on the parameter t. To solve it I need to specify x(0),y(0),x'(0),y'(0). I know how to solve it with NDSolve, (analytical solution doesn't work), and I want to make a list of different solutions with different initial conditions. I...

Can you fit data that is imported into Mathematica 8? I am just using the Import command, and I cannot figure out how to work with this data. I would really like to fit my curve. This is the code I used to import the data: Import[datafile.xlsx"]

I am trying to use Mathematica to fit a curve to these data points ListPlot[{{2*Pi/(1 - 0^2/16), 5 (3 - Log[2])}, {2*Pi/(1 - .05^2/16), 10 (3 - Log[2])}, {2*Pi/(1 - .1^2/16), 15 (3 - Log[2])}, {2*Pi/(1 - .15^2/16), 20 (3 - Log[2])}, {2*Pi/(1 - .2^2/16), 25 (3 - Log[2])}...

You can find problems with downloadable notebooks now http://www.mathhelpboards.com/f49/engineering-analysis-notes-2882/. If one boundary is insulated and the other is subjected to and held at a temperature of unity, we wish to determine the solution for the transient heating of the slab. The...

Mathematica notebooks that will numerical solve for eigenvalues, density plots, Fourier coefficients, and a few other options as well. There are 7 files for 1-D and 2-D. I would like to upload them but the forum says they are invalid file types. I believe the MHB community would greatly...

Dear all, I have a list of pairs say Li={{a,x},{b,y},{c,z}...}. I want to eliminate from this list all pairs that have their second part i.e the x, y, z...>1 and I was thing of using an If loop. Can anyone tell me how please... Thanks...

So I've several huge integrals to solve by hands and I would like to check my result with Mathematica. However I don't really know how to do so. Here is one of the several integrals I must solve: \int \frac{1}{2\pi \sigma _x \sigma _y \sqrt{1-\rho ^2 }} \exp \{ \frac{-1}{2(1-\rho ^2)} \left (...

Homework Statement I need to minimize the function Etrial[a] trial[x_] := E^(-a*x^2) Etrial[a_] := NIntegrate[1/2*D[trial[x], x]^2 + x^4*trial[x]^2, {x, -\[Infinity], \[Infinity]}]/ NIntegrate[trial[x]^2, {x, -\[Infinity], \[Infinity]}] Homework Equations The Attempt at a...

Hello every one, I need help on some mathematica run program. Suppose the following: 1) 2=<t=<1000 2) r=3+2Sqrt[2] 3) k=(r^t+r^(-t)-20)/4 4) n=2k+4 5) x=n/2-(r^t-r^(-t))/2Sqrt[2] I need to run the program For[t=2,t=<1000,t++ and only print if it found any...

I'm trying to solve a system of five nonlinear equations (degree 7) in Mathematica: Solve[{q (a^2 + b^2 (3 q^2 + r^2 + 8 t^2)) ((e - q)^2 - R^2 - 4 T^2)^2 + q ((e - q)^2 + R^2 + 4 T^2) - 2 (e - q) (r R + 4 t T) == 0, R (a^2 + b^2 (3 R^2 + (e - q)^2 + 8 T^2)) ((e - q)^2 -...

Count from "MatrixForm" in mathematica! Hi every one, I really need help on this task.. how do I Count only the zeros elements from a MatrixForm in MATHEMATICA Suppose I have a Matrix 100X100 full with numbers and I just need to know how many zero is there on this matrix thanks