Question

Find the vertex of the formula f(x)=ax^2+bx+c

Answer 1

i know the x coordinate is -b/2a but what is the y coordinate?

Answer 2

well you have the line of symmetry, so to find the vertex, substitute this value into the equation

f(-b/2a) = a(-b/2a)^2 + b(-b/2a) + c

so the vertex is

(-b/2a, f(-b/2a)

Answer 3

hmmm aren't you supposed to "complete the square" to get it?

Answer 4

yeah i don't think you can just leave it like that

Answer 5

well... do you know how to "complete the squre" then?

Answer 6

or do you know what a "perfect square trinomial" is?