to txuser: As far as I can tell, for Bahamas one neeeds a tourist visa. For Mexico - as long as the cruise is not more than 3 days, one does not need any visa (anyone in the world does not need a Mexico visa for a cruise upto 3 days). For entering back in US, either you can enter on a stamped visa or on AP. Pls check as well.
Discriminant of a Quadratic. The number D = b2 â 4ac determined from the coefficients of the equation ax2 + bx + c = 0. The discriminant reveals what type of roots the equation has. Note: b2 â 4ac comes from the quadratic formula.
Reaction quotient. In chemistry, a reaction quotient (Qr) is a function of the activities or concentrations of the chemical species involved in a chemical reaction. In the special case that the reaction is at equilibrium the reaction quotient is constant and equal to the equilibrium constant that appears in the expression of the law of mass action. A general chemical reaction in which Î± moles of a reactant A and Î² moles of a reactant B react to give Ï moles of a product R and Ï moles of a product S can be written as