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.
#c=10#. The solution to any of these problems is known as the quadratic equation: #x = (-b +- sqrt(b^2 - 4 a c))/(2a)#. The reason there is a #+# and a #-# in the top just means that there are two possible answers for x, and you need to try both signs to get both answers. The discriminant is just defined as the stuff in the square root of the expression: