Question

What is the vertex for the function? (You will want to find the axis of symmetry first.) Write as an ordered pair, leaving no spaces, such as (1,-4).
y = -3x2 + 6x

Answer 1

axis of symmetry is x=-b/(2a)=-6/(2*-3)=1
plug in 1 to y=-3x^2+6x to get your y-coordinate for the vertex

Answer 2

Can you further explain?

Answer 3

if you have a parabola in the form ax^2+bx+c the axis of symmetry is:
x=-b/(2a)

Answer 4

the vertex is at:
\[(\frac{-b}{2a}, f(\frac{-b}{2a}))\]

Answer 5

you can also rewrite this to a form you might more easily recognize:
\[a(x-h)^2+k\]
where (h,k) is the vertex
y=-3x^2+6x
y=-3(x^2-2x)
y=-3(x^2-2x+1-1)
y=-3(x-1)^2-3

Answer 6

sorry, last line should be:
y=-3(x-1)^2+3

Answer 7

thats called completing the square