Opened 5 years ago

Last modified 3 years ago

## #21946 closed defect

# solve(x==x, x) returns [x == r1] — at Initial Version

Reported by: | pelegm | Owned by: | |
---|---|---|---|

Priority: | minor | Milestone: | sage-8.4 |

Component: | symbolics | Keywords: | solve, days79 |

Cc: | Merged in: | ||

Authors: | Reviewers: | ||

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

Branch: | Commit: | ||

Dependencies: | Stopgaps: |

### Description

Not sure if it's a bug or a problem with the documentation, but without any assumptions on `x`

, `solve(x==x, x)`

returns `[x == r1]`

. The documentation does not state what `r1`

is, but gives the following example:

If there is a parameter in the answer, that will show up as a new variable. In the following example, "r1" is a real free variable (because of the "r"): sage: solve([x+y == 3, 2*x+2*y == 6],x,y) [[x == -r1 + 3, y == r1]]

However, without assumptions on `x`

, there's no reason to believe that `x`

is real.

**Note:**See TracTickets for help on using tickets.