Using the completing-the-square method, find the vertex of the function f(x) = –3x2 + 6x − 2 and indicate whether it is a minimum or a maximum and at what point.

Question

anonymous · Answer

i know you first put it in vertex form, but then how do you decide the max or mini thing

anonymous · Answer

https://www.khanacademy.org/math/algebra/quadratics/features-of-quadratic-functions/v/ex3-completing-the-square Here's a video on how to do them

mehek14 · Answer

@mollzlask do you know how to find a vertex?

anonymous · Answer

once you get it in vertex form, yes

mehek14 · Answer

how about with the formula
$x=\dfrac{-b}{2a}$

anonymous · Answer

oh lol how

anonymous · Answer

so with that the vertex is 1,1 right?

mehek14 · Answer

the original equation is 
$ax^2+bx+c=0$

in the equation you have, a = -3 , b = 6 , c = -2

mehek14 · Answer

yes the vertex is 1,1

anonymous · Answer

okay, so is that the minimum then?

mehek14 · Answer

look at a in your equation
if it is positive, then it opens upwards and (1,1) is the minimum
if it is negative, then it opens downwards and (1,1) is the maximum

mehek14 · Answer

so what do you have as a in your equation?

anonymous · Answer

its positive

mehek14 · Answer

first tell me what a is in your equation

mehek14 · Answer

it's the coefficient of $x^2$

anonymous · Answer

3

anonymous · Answer

oh wait lol

mehek14 · Answer

it has a negative sign in front of it

anonymous · Answer

im stupid im sorry

mehek14 · Answer

no it's fine

mehek14 · Answer

so it is -3

anonymous · Answer

thank you for helping me!!

mehek14 · Answer

np
so since a is negative, the parabola would open downwards, and (1,1) would be the maximum.