Question

What is the vertex for f(x)=x^2 -4x-3?

Answer 1

can't wait to see this...

Answer 2

you want to complete the square. when you have an equation in the form:
\[x^2+bx+c\]first you divide b by 2 and square the result:
\[(-\frac{4}{2})^2 = 4\]
You add and subtract that value to your function:
\[x^2-4x+4-4-3\]
Then you group and factor:
\[(x^2-4x+4)-4-3 = (x-2)^2-7\]
So the vertex is (-2, -7)

Answer 3

...

Answer 4

i knew it!

Answer 5

It was 2,-7

Answer 6

well(2,-7)

Answer 7

whoops, sign error >.< its supposed to be what you said.

Answer 8

no one want to use the oh so simple
\[x=-\frac{b}{2a}=-\frac{-4}{2\times 1}=2\]

Answer 9

(-b/2a,-D/4a)
a = 1 ,b =-4 D = 16+12 = 28 => (2,-7)

Answer 10

lol

Answer 11

i hate that formula!

Answer 12

first coordinate is 2, second is what you get when you replace x by 2

Answer 13

nothing could be simpler

Answer 14

I prefer simple lol

Answer 15

x = 2, y = 4-8-3=-7 done vertex is (2,-7) finito stick a fork in it

Answer 16

>.>

Answer 17

everyone here hates this simple simple simple formula

Answer 18

no one objects to
\[\frac{-b\pm\sqrt{b^2-4ac}}{2a}\] but i you erase the radical part they have a fit. why is that/

Answer 19

just get rid of the radical and you have
\[-\frac{b}{2a}\] easy easy easy

Answer 20

all that stupid completing the square work and keeping track of what you add and subtract? for the birds. it is always
\[-\frac{b}{2a}\] and the explanation is simple too

Answer 21

I cant stand when they throw all that extra crap in there, they're just going to have you take off

Answer 22

exactly. the point is, if you know that the first coordinate is
\[-\frac{b}{2a}\] then you know what the second coordinate is by substitution. you do not need to keep track all the way down the line