Questions on the analytic and numeric equation solving functions of Mathematica (Solve, Reduce, NSolve, FindRoot, DSolve, RSolve, etc.).

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0
votes
1answer
78 views

Transforming from implicit Cartesian form to a parametric form [closed]

First equation $((1.2 x)^2 + (1.4 y)^2 - 1)^3 - (1.3 x)^2 y^3 == 0$ I wanna transform it into a parametric equation. I spent a much of a day working on it without success. The equation describes the ...
3
votes
1answer
89 views

Trying to find a temperature profile with a nonlinear 2nd order ODE. NDSolve very sensitive to seemingly arbitrary constant

I am trying to solve this differential equation for a heat transfer problem: \begin{equation} kt\frac{\partial^2 T}{\partial x^2} = \epsilon \sigma T^4, \ \ \ T(0) = T_0, \ \ \ \frac{\partial ...
0
votes
3answers
85 views

Interactive Application using Manipulate for Fibonacci Series

I am working on creating interactive app using Manipulate function on fibonacci series using SeriesCoefficient. I want to plot the fibonacci numbers based on the slider of Manipulate function. I ...
3
votes
1answer
66 views

Reduce is not giving answers, only verifies it's true

I'm trying to find a range for {q1,q2} with the conditions listed such that U1R >= U1S ...
0
votes
1answer
132 views

loops and data file

I have solved a set of equations for a specific given data point and restricted my solutions to 100. then I did TrimmedMean to have the mean value of all 100 ...
0
votes
0answers
32 views

Solving for limit of integration with a piecewise function (FindRoot vs NSolve) [duplicate]

I am trying to solve for the limits of integration using a piecewise function. I'm doing this in a loop over a list of data, mostly because I'm not well-versed enough in Mathematica to make this a ...
4
votes
2answers
186 views

Solve System of Equations with Constant Ratios

I'm currently trying to use Mathematica to solve a problem for my fluid mechanics class. I need to solve the following system of 3 equations: $$\begin{align*} \dfrac{h}{a} &= \cot ...
1
vote
0answers
58 views

NMinimize / adding constraints

I have a quick question: in question:Solving an ODE with boundary conditions at infinity and 0//different problems, I asked for help concerning a differential equation- however, the whole solving ...
0
votes
0answers
27 views

find indeterminates (which are function of time) of an expression [duplicate]

Is there a function in Mathematica so as to find the indeterminates of an expression? When I used Maple, there was the function indets. Is there a similar function in Mathematica? Here an example ...
0
votes
1answer
43 views

Use elements of a convex sets to solve equations [closed]

i try to do sth. like this A=Solve[{x>=5, y>=3, x<13,y<13} ,{x,y}] which gives me a convex set and then ...
5
votes
3answers
115 views

On Solutions of Diophantine Equation

By Mathematica, I try to obtain solutions of Diophantine equations such as: $$F_{n_1}F_{n_2}\cdots F_{n_k}+1=F_t$$ where the sequence $\{F_n\}$ is the Fibonacci sequence,$n_1 < n_2 < \cdots ...
3
votes
1answer
67 views

Finding inconsistencies in a system of equations

I am a rookie in Mathematica and apologize in advance. Here is my question: Are there any tools, built in the program, of detecting inconsistency in a nonlinear system of equations? Whilst finding ...
9
votes
4answers
262 views

How to find the next root larger than a specified value, numerically?

I would want to have a general-purpose, reasonably robust method of finding the next numerical root above a specific value of x. I'm stumped by the fact ...
-1
votes
1answer
76 views

How I show the case numbers on a plot? [closed]

I have the following code: ...
1
vote
1answer
96 views

Solve differential equations with an initial condition in the form of a limit as $t\rightarrow \infty$

I want to solve the following differential equation with the initial condition This is known as the Bunch-Davies vacuum, and the above are equations (4.1) and (3.37) from this paper Here is ...
1
vote
1answer
57 views

System solution [closed]

How to solve this system using Mathematica. eq1 := xsin[y] - 3.5 cos[y] - 4.5; eq2 := -xcos[y] - 3.5 sin[y] + .4; Solve[eq1, eq2, {x, y}] This does not work.
2
votes
2answers
73 views

Finding zero of nonlinear simultaneous equations [closed]

I'm trying to find the zero of nonlinear simultaneous equations defined in myfun1 and myfun2: ...
2
votes
2answers
76 views

Integral equation solving

So there is this equation that I have to numerically solve for T: Q/(3nRT) = f(T/300) - f(T/77) Here Q = 920.364, n = 0.24, R = 8.314 while f is defined as the ...
1
vote
0answers
62 views

DSolve throws an error about Solve and returns unevaluated [duplicate]

I evaluate: DSolve[{2*y[x] + y'[x]^2 + a*x^b == 0}, y[x], x] During evaluation of In[26]:= Solve::ifun: Inverse functions are being used by Solve, so some ...
1
vote
3answers
147 views

NSolve or Solve or FindRoot

I need to solve this equation: A == M/(f d/2 (1 + Sqrt[1 - 3.53 (M/(b d^2 c))])) to find M, with: A = 0 to 19635 for intervals of 5 f = 500 d = 100 to 500 ...
0
votes
1answer
45 views

Solving a system of four equations [closed]

I'm trying to run this: ...
5
votes
2answers
102 views

Rewriting expression in terms of factor

I have two expressions: expr = (a - R)^2 (a + 2 R)/(2 R^3); factor = 1 - a^2/R^2; I would like to write expr in terms of ...
2
votes
1answer
76 views

Can not Solve FinancialDerivative for volatility

Although Solve can solve FinancialBond for an input parameter (e.g. par) given the price of a bond: ...
1
vote
1answer
107 views
0
votes
0answers
27 views

Solve does not give solutions to all variables [duplicate]

I have a beam with $n$ points and I have to find a numerical solution of the axial force using Finite difference method Here is my code ...
1
vote
1answer
76 views

DSolve to make the path of a ball in a rotating turntable

I have two equations from a analisys of the following situation. A ball starts to move from the center of a Turntable (rotating disk). I tried to solve these equations on Mathematica but the ...
3
votes
4answers
174 views

Find the minimum positive-integer value which meet the requirement

If the equation is Mod[515 Sum[10^(3 d), {d, 0, n}], 53] == 0 Then I can get the minimum positive-integer value of n. ...
4
votes
1answer
217 views

How to speed up calculation of this equation (FindRoot)

I have come up with the following functions, and I need to calculate a value, in order to have a condition valid. In my problem, all data are given, and I need to calculate variable l. I am using ...
4
votes
5answers
377 views

Solve for exponents

I have this problem that I"m trying to work out: Here's my attemp: me = 0.51109991 mp = 938.2723 mpe = mp/me Solve[(2^n)*(3^mm)*(\[Pi]^p) == mpe, {n, mm, p}] ...
0
votes
1answer
78 views

Solve exp(x) = x [closed]

I need help to solve the function Exp[x] = x. I tried using Solve but I got an error that told me to use ...
1
vote
0answers
56 views

How to solve Irrational equation in non radical form

I have a problem how to solve this irrational equation. It is important to note that it is not necessary to present roots in radical form (impossible). For me it is important to have roots in this ...
4
votes
0answers
67 views

Why does Mathematica gives a solution which is not in the domain of the cot function? [closed]

I've tried to solve the equation $\cot \theta = 2 \cot 2\theta$ with the command Reduce and Mathematica gave $\theta = n\pi$ as solution, with $n$ an integer. But ...
-1
votes
2answers
79 views

How can I make a command to write out the solution of the absolute value inequality?

I've written this source code, but I can't finish it yet. ...
3
votes
1answer
73 views

plotting after solve does not display anything

I'm quite new to Mathematica language, I am trying to figure out where I am making mistakes in Plotting a specific function that depends to other variables: I want to plot ...
0
votes
0answers
54 views

How can I make an amateur demonstration to solve absolute value equations and inequalities?

I would like to make a program which can solve absolute value equations and inequalities, but I'm a beginner of using the mathematica. I found amazing good demonstrations at the web-page of ...
3
votes
1answer
95 views

Unable to solve equation for a variable by any method

I am looking to solve for the value of r when the derivative of the expression ...
0
votes
0answers
39 views

Both Solve and FindRoot fail to solve my equation [duplicate]

I am trying to solve for r when the equation ...
1
vote
1answer
87 views

Solving trigonometric functions in Mathematica

I am new to Mathematica language and recently I had the need to solve the following equations with two variables, A and B: ...
0
votes
1answer
44 views

Using the Solve function [closed]

I am new to using Mathematica and am attempting to find the roots of a function using the Solve[] function. I can replace $f[x]$ within Solve[] with the actual function and it will work that way, but ...
1
vote
1answer
81 views

System of nonlinear equations

I am new at mathematica, and I am trying to solve the following system of four equations (f11==0 ,f12==0 , f13==0 , f14==0) under mathematica 10 , they depend on the real variables "alpha, beta, R and ...
1
vote
0answers
39 views

solving with numerical methods [closed]

Hi I would like to solve the equation below in Mathematica.Since I am a beginner I can not solve it with NSolve and Solve.I don't know why.Do you have any idea?! ...
4
votes
0answers
74 views

Improve Accuracy of FindRoot

This is a follow up question to an earlier questions I asked. The link is: Product of $N\ 2 \times 2$ matrices and subsequently solving an equation dependent on the product As I am new here, I am not ...
4
votes
0answers
104 views

Why does Solve work in v9.0.1 but not in v10.3.1

I want to solve the following DE $$ P'=k(M-P)P, P[0]=53.08, P[50]=23.192, P[100]=76.212.$$ The Mathematica command is ...
1
vote
0answers
43 views

How can I use x->Root outputs from Solve? [duplicate]

Do not understand the meaning of the output given by Mathematica to this equation: ...
1
vote
3answers
84 views

How to use Solve command? [closed]

I have written a code like follows: ...
1
vote
0answers
35 views

complex algebra with Solve function [closed]

I wanted to solve this complex expression for L, Solve[(1/(R + (1/Iwc)) + (1/(R + IwL)))^-1 == R, L] where I is sqrt(-1) and mathematica is out putting {}. Does ...
0
votes
0answers
66 views

Select positive elements from a list of solutions

I'm solving two equations with two unknowns ...
1
vote
1answer
52 views

Getting the conditions for equation to be solvable

I have a parametric equation to be solved, but I do not actually care for the solution. I only want to know the range of parameters for which the equation has a solution. Is there a way to get the ...
0
votes
0answers
137 views

Why is Mathematica not solving this equation?

Every time I am trying to solve this equation Mathematica is just not doing anything. First time is showed error as quantity is not quantified or something. But since then whenever I am trying to ...
1
vote
1answer
80 views

Having issue for solving a system with seven equations

I have a system with seven equations and three constrains. I tried to solve them using NSolve, but it takes forever without getting any result. Also, I tried it ...