1. The problem statement, all variables and given/known data Give a useful negation for: [itex]\forall x > 0, \exists y > 0 s.t. y^2 = x[/itex] 2. Relevant equations 3. The attempt at a solution I'm not sure how to do this, I have [itex]\exists y > 0 s.t. \forall x > 0, y^2 = x[/itex] Which says "there exists a y that for all x, y^2 = x"....which is obviously incorrect, as there is no y that when squared equals EVERYTHING.