A parabola can be represented by the equation y2 = –x. What are the coordinates of the focus and the equation of the directrix? focus: (negative one-fourth, 0); directrix: x = One-fourth focus: (one-fourth, 0); directrix: x = Negative one-fourth focus: (–4,0); directrix: x = 4 focus: (4,0); directrix: x = –4

Over the course of the school year, you keep track of how much snow falls on a given day and whether it was a snow day. your data indicates that of twenty-one days with less than three inches of snow, five were snow days, while of the eight days with more than three inches of snow, six were snow days. if all you know about a day is that it is snowing, what is the probability that it will be a snow day?

Find the measurement of angle b in the following triangle

Fracisco's game involves 3 green, 2 yellow, 4 red, and 3 black marbles. if he randomly draws three marbles from the bag, without replacement, what is the probability that he will draw yellow, and then red, and then black? a)1/192 b)1/72 c)3/220 d)1/55