Question

I need to find the equation of a parabola that has a vertex of (-3,0) and is opening upwards.

Answer 1

I try to help, but forgot the formula of parabola, do you remember?

Answer 2

I have not learned that actually all I know is the factoring method and quadratic formula

Answer 3

ok, google now, both us , OK? and then we compete, play or not?

Answer 4

I tried googling how to do this but no answer

Answer 5

not how to do, we google " what is the vertex formula of a parabola" .

Answer 6

Ok

Answer 7

3,2,1 get go

Answer 8

hey, I got it first, I won, so, you have to find out the meaning of the formula. ok?

Answer 9

take a look at http://www.mathwarehouse.com/geometry/parabola/standard-and-vertex-form.php

Answer 10

I have it but I am confused on how to use it

Answer 11

hehe, loser, now your turn, explain me, what h,k mean?

Answer 12

Ummm. This website has nothing on how to go from a vertex point to an equation

Answer 13

so, what you have from your website?

Answer 14

I had the exact same website but it is not what I am asking

Answer 15

How do I go from a vertex (-3,0) To an entire equation of the parabola
?

Answer 16

hhmmm I don't know either, ok, get help from other, you tag someone.

Answer 17

@e.mccormick

Answer 18

@Mertsj

Answer 19

Does anyone know

Answer 20

the general form is

\[y =a(x -h)^2 + k\]

where (h, k) is the vertex and a is a constant

so you have

\[y = a( x - 3)^2 + 0\]

Answer 21

in your question I'd assume a = 1

Answer 22

I do not know what a is

Answer 23

hold on!! it's (x+3) not (x-3)

Answer 24

since our h is -3 , am I right?

Answer 25

idk what the a is

Answer 26

H should be -3?

Answer 27

well then its

\[y = a( x + 3)^2 + 0\]

vertex ( -3 , 0) and let a = 1

Answer 28

yes, !! in general , whatever a is, we must have a positive to have the parabola upward.

Answer 29

so now what?

Answer 30

thats partly correct

as

\[y = ( x+ 3)^2 + 0....and.....y = 4(x + 3)^2 + 0\]

have the same vertex but are different graphs...

Answer 31

well all you need to do is simplify

\[y = (x + 3)^2 \]

just distribute

Answer 32

\[x ^{2} + 9?\]

Answer 33

you are missing the middle term 6x

and its y = ......

Answer 34

Wait!!

Answer 35

I hand off, @Plungedcashew good luck, you have a very high smartscore person helps you. the game is not fun anymore

Answer 36

I get to match parabolas to equations

Answer 37

And one of the possible answers is actually y=(x+3)2

Answer 38

no more work to do.

Answer 39

Wait so..

Answer 40

Why is it x+3?

Answer 41

Oh I got it!

Answer 42

Thanks sooo much man. How do I give you a triple AAA rating?

Answer 43

ok.... here is the important bit

the vertex form of a parabola is

\[y = a(x - h)^2 + k\]

(h, k) is the vertex.

In your question the vertex is (-3, 0)

so h = -3 and k = 0

substitute them for the answer.

Answer 44

Thanks man. i am glad you came along for me!