next up previous contents index
Next: rationalSolution Up: Supported functions Previous: normalize   Contents   Index


polynomialSolution


Usage

polynomialSolution(L, g)


Parameter Type Description
L ${\mathbb{Q}}[n,E]$ A difference operator
g ${\mathbb{Q}}[n]$ A polynomial


Description

polynomialSolution($L,g$) returns either $[p]$ where $p \in {\mathbb{Q}}[n]$ satisfies $L p = g$, or $[]$ if $L y = g$ has no solution in ${\mathbb{Q}}[n]$.


Remarks

polynomialSolution($L,0$) returns $[0]$ only when $L y = 0$ has no nonzero polynomial solution.


Example

A particular polynomial solution of

\begin{displaymath}
y(n+1) - y(n) = 5 n^4
\end{displaymath}

can be computed in the following way:
1 --> p := polynomialSolution(E-1,5*n^4);
2 --> tex(p);

\begin{displaymath}[ n^{5}-{{5} \over {2}}\,n^{4}+{{5} \over {3}}\,n^{3}-{{1} \over {6}}\,n ]
\end{displaymath}


Usage within MAPLE

When using polynomialSolution from inside MAPLE, the output is modified and either a polynomial solution in $p \in {\mathbb{Q}}[n]$ or $[]$ is returned. So the above example in MAPLE would be:
> polynomialSolution(E-1,5*n^4,E,n);

\begin{displaymath}
n^{5}-{{5} \over {2}}\,n^{4}+{{5} \over {3}}\,n^{3}-{{1} \over {6}}\,n
\end{displaymath}


See Also

kernel, rationalSolution


next up previous contents index
Next: rationalSolution Up: Supported functions Previous: normalize   Contents   Index
Manuel Bronstein 2002-09-04