# Questions tagged [difference-equations]

Tag for the usage of RSolve, RecurrenceTable, DifferenceRoot, and other functions related to difference equations.

195 questions
Filter by
Sorted by
Tagged with
75 views

53 views

### Solving a system of recurrence equations

Can anybody help me with the following code for solving a system of nonlinear recurrence equations. When I evaluate the kernel and run it, the output is the same is my input as if the Mathematica is ...
38 views

### Recurrence Relation based on Vectors

I am new to Mathematica. I try to solve a recurrence relation based on vectors. So a[n] is a vector for all n (as well as ...
89 views

### Solving a recurrence relation with variable coefficients

I am trying to solve this recurrence inequality for $a_n$, hopefully in terms of $a_0，a_1，c$ and $x$, $$(1-x)a_{n+1} \le xa_n + (1+x)a_{n-1} + c\quad\forall\ n\ge1$$ What I tried: RSolve. But ...
40 views

### Why does RSolve not give what I expect?

I have a model based on a digraph G. I construct a system of difference equations, modelFull, as seen below. ...
35 views

### Avoid Recursion in lag and difference operations

I have a panel data situation and I'm interested in taking lags and differences and using Mathematica to simplify the algebra of the result. Currently I'm working with a model like this: ...
81 views

### How can I solve this systems of differential equation and show a plot?

$$\frac{\mathrm du}{\mathrm dt} = 1 - u \mathrm e^{\epsilon(8q-1)}$$ $$\frac{\mathrm dq}{\mathrm dt} = u \mathrm e^{\epsilon (q-1)} - q$$ $0 \leq \epsilon \leq 0.1$ $u(0) = 0$ and $q(0)=0$ ...
36 views

### Residues of products

i have the following problem: My function is given by: $(cz^{-1}+aq^{-j}-bq^{-2j}z)\prod_{m=1}^{Q-1}\frac{qz-z_{m}}{z-z_m}+(-cz^{-1}+dq^{j}+bq^{2j}z)\prod_{m=1}^{Q-1}\frac{q^{-1}z-z_{m}}{z-z_m}=E$, ...
39 views

### fisrt 5th iterations of a sequence of functions: integro-differential equations [closed]

Please I am struggling to compute with mathematica the first 5th iterations of the sequence of functions $u[n,t]$ satisfying the integro-differential equation Please help me with the code. Patrick
152 views

### Using NIntegrate in Finite Difference Derivative method

I'm trying to solve a second order differential equation using the code given by @xzczd here which is based on this. What this ...
79 views

### Zeros of a rational fraction sequence

This is a follow-up of the question Finding a function/differential equation from a 2nd order recurrence relation, I asked yesterday. The reason why I didn't edit the original question was that in ...
72 views

156 views

### Guessing recursion in rational functions

I want to know if there is a package in Mathematica that can give back some recursion given a list of polynomial in $f_{n}(h)$. For example I know there exists package RISC guess that where I give ...
80 views

### Solving a boundary-value recurrence relation

I would like to solve a recurrence relation of the form ...
47 views

### How many solutions are there in this equation $u_{2018}=0$?

I have a sequence $(u_n)$ so that $u_1=a$ and $u_{n+1}=4u_n (1-u_n)$, for all $n=1,2,\ldots$. How many solutions are there in this equation $u_{2018}=0$? I tried ...
45 views

### RSolveValue syntax

Can't see anything wrong with this: sol4 = RSolveValue[{a[n + 1] - 1.2*a[n]*(1 - a[n]) == 0, a ==0.1}, a[n], n] But I just get an echo from Mathematica
88 views

### Vector and matrix use in RecurrenceTable

Why is this code snippet that uses matrix and vector elements work? ...
70 views

### Recurrence table doesn't like non-linearity?

When I evaluate the following RecurrenceTable expression ...
69 views