How do you find two quadratic function one that opens up and one that opens downward whose graphs have intercepts (-1,0), (3,0)?
Please see the explanation.
Because the quadratic function is zero, when
where k is an unknown constant that one can use to force the quadratic to pass through a point with a non-zero y coordinate.
I will multiply the factors:
I will chose
Now I will choose
Equation  opens upward and equation  opens downward; both have the same intercepts,