sympy/sympy — pull request #971 by Krastanov (2012-01-14 11:17:29+00:00)
Title: Additional documentation to `check` in `solve()`

Document the cases when check=False gives right or wrong answers.

With `check=True` you may miss solutions at removable
singularities. But with `check=False` for the moment one gets right answers
at removable singularities of the type `O(x**p)/O(x**p)` for `p > q` but
wrong answers if `p <= q` (only `p == q` is still a removable singularity).
The example of `solve(sin(x)/x, check=False)` shows that.

Concerns issue 2981.