The Centers for Disease Control and Prevention (CDC) is recognized as the lead United Statesagency[?] for protecting the health and safety of people by providing credible information to enhance health decisions, and promoting health through strong partnerships. CDC serves as a national focus for developing and applying disease prevention and control (especially infectious diseases), environmental health[?], and health promotion[?] and education[?] activities designed to improve the health of the people of the United States.
... x, both of which are real. (Geometrically, this means that the parabola intersects the x-axis in two points.)
If the discriminant is negative, then there are two ...