Question

please help

Answer 1

Which are the coordinates of the vertex of the graph of the function y = 3x^2 - 12x + 3

A. (-2, 29)
B. (2, -15)
C. (2, -9)
D. (-2, 15)


@Embryo apparently the answer was D :(((

Answer 2

Answer is C. (2, -9)

Answer 3

@Blank  that's what i got too, but she says the answer is wrong? I think the answer key is wrong then

Answer 4

-6x -12 = 0

x =12/-6
x=-2

Plug in -2 to the original function:

y = -3(-2)^2 -12(-2) +3

y = 15

(-2,15)

Answer 5

I just submitted it and I got it wrong, it was D.

Answer 6

it WAS d lol

Answer 7

it IS d

Answer 8

I strongly disagree. Something is wrong or missing. http://www.wolframalpha.com/input/?i=y+%3D+3x%5E2+-+12x+%2B+3+vertex

Answer 9

is it -6x-12 or 6x-12??? @jinxhead20

Answer 10

the answer is d, blank

Answer 11

NEGATIVE 6

Answer 12

obviously

Answer 13

If you solve it to become the general form of a parabola, you get the equation\[y=3(x-2)^2-9\]which is a parabola located at (2,-9)

Answer 14

*facepalm*

Answer 15

but question is 3x^2

Answer 16

if the answer key says that it's D then, it IS D

Answer 17

I said it once and I'll sAY IT AGAIN
-6x -12 = 0 x =12/-6 x=-2 Plug in -2 to the original function: y = -3(-2)^2 -12(-2) +3 y = 15 (-2,15)

Answer 18

Remember that axis of symmetry question you had trollface, you calculated\[X=-\frac{ b }{ 2a }\]you can also use that here, a=3, b =-12, plug that in and you get\[X=-\frac{ b }{ 2a }=-\frac{ -12 }{ 2*3 }=\frac{ 12 }{ 6 }=2\]plug in 2 into the original to find that y=-9\[y=3(2)^2-12(2)+3=12-24+3=-9\]i can't accept that the answer is wrong, it means there is a bad answer key

Answer 19

omg, you guys have been using the axis of symmetry method this whole time, but have been forgetting the extra negative!

Answer 20

@jinxhead20 You are finding a solution to the problem and not the vertex. Look at this page. The vertex is at the bottom or top of the parabola. Obviously, (2, -9) is the vertex. (-2, 15) is not. @trollface You could actually talk to your teacher and say that the answer is wrong.

Answer 21

http://www.uiowa.edu/~examserv/mathmatters/tutorial_quiz/geometry/findingvertexofparabola.html

Answer 22

Why is this so complicated? lol. Sorry that you got the answer incorrect.

Answer 23

It can't be helped when the answer key is what's wrong, it just causes the students to run around without their heads and believe that they did something wrong, when in fact, they didn't

Answer 24

OMG!!!!!! ALL THIS IDIOTNESS IS GIVING ME A MIGRAINE!!!!!!

Answer 25

i'LL GOOGLE THE ANSWER

Answer 26

OH WAIT NO...LET ME THINK....

Answer 27

woah, didn't mean to start a debate/argument here...

Answer 28

if y = ax^2 + bx + c, the x coordinate of the vertex is x = -b / (2a)
So for example, if y = 3x^2 - 12x + 3, the x coordinate is x = -(-12) / (2•3) = 12/6 = 2
then just plug that in to get the y coordinate.
3(2^2) - 12(2) + 3 = 12 - 24 + 3 = -9
so vertex = (2, -9) sO YOU GUYS WERE RIGHT LOLOLOL ROFLOL

Answer 29

Ughh, here we start again. It's already solved, the answer is (2, -9). End of debate. :) Now can we just live now?