Opened 7 years ago

Last modified 7 years ago

## #16793 new defect

# ODE solve fails as assumption is not used by desolve

Reported by: | rws | Owned by: | |
---|---|---|---|

Priority: | major | Milestone: | sage-6.4 |

Component: | calculus | Keywords: | assume, maxima |

Cc: | Merged in: | ||

Authors: | Reviewers: | ||

Report Upstream: | N/A | Work issues: | |

Branch: | Commit: | ||

Dependencies: | Stopgaps: |

### Description

sage: var("a,b,c,k,r,q,i,j,m,n,p,s,t,x,y,z") (a, b, c, k, r, q, i, j, m, n, p, s, t, x, y, z) sage: assume(x^2+(-4*n-2)*x+1>0) sage: f=function('f',x) sage: desolve(x*diff(f(x),x,2)+(1-x)*diff(f(x),x)+n*f,f,ivar=x) ... TypeError: Computation failed since Maxima requested additional constraints; using the 'assume' command before evaluation *may* help (example of legal syntax is 'assume(x^2+(-4*n-2)*x+1>0)', see `assume?` for more details) Is x^2+(-4*n-2)*x+1 positive or negative?

(the ODE of the Laguerre polynomials)

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