According to the Sympy docs, the solve() command expects an equation to solve as being equal to 0.
How can I solve equations not in that form?
What the docs are saying is that if you do something like
>>> solve(x**2 - 1, x)
Then solve is implicitly assuming that x**2 - 1 is equal to 0. If you wanted to solve x**2 - 1 = 2, then you could either subtract 2 from both sides, to get
>>> solve(x**2 - 1 - 2, x)
or you could use the Eq() class
>>> solve(Eq(x**2 - 1, 2), x)