Questions tagged [equation-solving]

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

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Unbounded solution at boundaries with few combination of values in this BVP solution

I had asked a question here regarding solution to a BVP problem. bbgodfrey provided an excellent answer using the method of integrated least squares. However, for a few specific set of values of ...
16 views

Solve command fails when applied to this equation?

I have the following equation (exp1=1) which i would like to solve for w: ...
65 views

Plot the solution and Inverse as well

I used this code to solve an equation and now I would like to plot the solution with its inverse. I can't get some figures?!! ...
22 views

How to combine two manipulated plots over the same domain, and how to add an assumption to the given code?

I have these four 2-variable functions: ...
151 views

NDSolve WhenEvent Partial Evaluation of a Function

I want to obtain an intermediate result from NDSolve using WhenEvent.
24 views

Private variable issue in a function environnement

I have the following matrix which represents an input from a .txt file. The first column gives the name of the random variable, the second the probability law, the third the parameters related to the ...
36 views

two times DSolve the equations [closed]

I was working those equations but for the second DSolve I have problem?! ...
121 views

How can I solve this system of 6 simple quadratic diophantine equations in four variables?

I generated this text file containing tuples $(\sqrt{s}, \sqrt{t}, \sqrt{u}, s,t,u,t+u,t+u-s,t-s)$ where the six variables $s,t,u,t+u,t+u-s,t-s$ are all squares. An excerpt of the data set is: ...
153 views

Can I get the given plot without calculating the roots numerically? Is it possible to use Manipulate/Animate to get a continuous line of the points?

I have two functions $F(x,y)$ and $G(x,y)$ for $0<x\leq3$ and $-1\leq y \leq1$. Given a specific value of $y$, I want to find those values of $x$ for which we have $F=0$ and $G\neq \pm 1$. For ...
147 views

How do we solve this system?

consider: \begin{align} \dot S &= A-\beta S(I+\rho_1 T)-(\mu+p)S\\[1ex] \dot V &=pS-\rho_2 \beta V(I+\rho_1 T)-\mu V\\[1ex] \dot L &=l \beta S(I+\rho_1 T)+\rho_2 \beta V(I+\rho_1 T)-(\mu+\...
45 views

2 equations 2 Unkowns at loop variable input [closed]

I want to solve a system of equations 2 equations 2 Unknowns at loop variable input at the equations how could I do that ?
76 views

NSolve syntax for region

I am trying to solve these simultaneous system of equations only in a specified rectangle going from -100<x<100 and -100<y<100. But I think I am making a syntax error and hence I m not ...
98 views

LinearSolve with 4 variables and 3 equations [closed]

Is it possible to find a solution or at least run LinearSolve when there are 4 variables and 3 equations. For example: a + b -3c + 4d = 4; 2a + 5b -6c +2d = 15; 3a -4b + 5c -3d = 10.
75 views

A problem when solving an equation with symbolic variables

I asked a question a couple days ago and received a solution that worked for me at the time. But now I am seeing that the proposed solution fails for some other cases I need. For example, if I just ...
57 views

Assumtion on Solve and DSolve

How to fix this problem I can't get something from this!! ...
85 views

Symbol of system of equations

I'm wondering if there is a way to use the symbol (the left curly bracket) of a system of equations. So far I found only the following "symbol": I need to remove the two conditions. EDIT2: ...
40 views

Using the symbol of the system of equations [duplicate]

Part 1 I'd like to know how to use the symbol of system of equations (left curly braces). I tried the following code: Part 2 How can I add a third equation?
129 views

Solving equations with symbolic variables

I have the equations ...
59 views