A parabola is a squared distance from a turning point, stretched upward or downward.
WHAT HAPPENS IF…Make a parabola whose vertex is (1, −2) and that opens downward.
Interactive exploration
Preparing your experiment…
Connect the picture to the ideay=a(x−h)2+k
The square is smallest at x = h. If a is positive, the vertex (h, k) is a minimum; if a is negative, it is a maximum. Setting y to zero locates real roots when they exist.
A detail that matters
If a = 0, the function is constant, not a parabola.