Question

Which part of the quadratic equation determines that it opens up or down??

Answer 1

Try drawing y=-x^2 and y=x^2.

Answer 2

http://www.algebra.com/algebra/homework/quadratic/Quadratic_Equations.faq.question.219414.html

Answer 3

this is a better one http://www.algebra-class.com/quadratic-functions.html

Answer 4

let \( y = ax^2 + bx + c \) be your function, if \( a > 0\), it open upward, if \( a < 0\) then it opens downward.