Hi Mitchell,
One way
Solve[2 Sin[x]^2 - Sin[x] - 1 == 0 && 0 < x < 2 Pi, x, Reals] // DeleteDuplicates (* {{x -> π/2}, {x -> (7 π)/6}, {x -> (11 π)/6}} *)
Thanks so much. I also found that Reduce[] works real well also. Additionally you do not need to suffix // DeleteDuplicates to the Reduce[] expression.
Thanks again,
Mitch Sandlin
