Question

explain how the sign of a in the equation y=a(x-h)2+k tells you whether the parabola has a minimum or maximum value

Answer 1

If a is negative the parabola has a minimum because it curves down. If a is positive is curves up so it has a minimum. Do you need more description than that?

Answer 2

yes please what the question was asking is how does "a" distinguish whether it positive or negative

Answer 3

If "a" is negative the parabola has a minimum because it curves down. If "a" is positive the parabola curves up so it has a minimum.