Question

how do you find the equation of a graph(parabola)?

Answer 1

locate the vertex and one point if possible

Answer 2

and after that what do i do?

Answer 3

give me the points and I will help you as you work it out

Answer 4

(-1,1) point
vertex = (1,-2)

Answer 5

\[y=a(x-h)^2+k\]
vertex is (h,k) and your point is (x,y)
sub and solve for a

Answer 6

tell me what you get

Answer 7

(3/4)

Answer 8

this is your a value
sub it back into the equation I gave you but keep (h,k) only
tell me what you got

Answer 9

by the way your a is correct

Answer 10

y=-(9/16)x^2 - -(9/16) - 2

Answer 11

\[y=\frac{3}{4}(x-1)^2-2\]

Answer 12

where is your x to the first power?

Answer 13

oh just leave it as that. dont distribute the 3/4

Answer 14

yes this is known at standard form

Answer 15

i see. but the answer for the problem is y=x^2 - x -2

Answer 16

where you given any information other than the point and vertex?

Answer 17

vertex is (1/2,-9/4)

Answer 18

I fixed it, I am sure. I am also doing my calculus homework at the moment

Answer 19

I am just wondering what information was given, could be a typo on the asker part

Answer 20

how did you achieve this ^

Answer 21

Luis did completing the square

Answer 22

okay im going to try that

Answer 23

@Luis Rivera -7/4 I believe Luis your y value is incorrect

Answer 24

what F/N Means in the vertical axis?????

Answer 25

@Bhavnazoon what is F/N?

Answer 26

yeah i got -7/4 as well

Answer 27

but what info were you intially given? methods should not matter , solution will be the same

Answer 28

its rather hard to draw it

Answer 29

@Luis Rivera Thanks I will check it out. I just do the homework for fun. I am just helping a relative - I already completed all of my degrees

Answer 30

@scottiboib Can you scan your graph and attach it?

Answer 31

ok I will think about it. I just do this for fun...... :)

Answer 32

i dont have a scanner sorry

Answer 33

how do i change this to vertex by completing the square? y=2x^2-12x+8

Answer 34

first you need to make x^2 have a 1
so first factor out 2

Answer 35

y=2(x^2-6x+4)
complete the square with 6
(6/2)^2

Answer 36

try it I will double check your work

Answer 37

would it be y=2(x-(6/2)+13

Answer 38

correction y=2(x-(6/2))^2+13

Answer 39

sorry doing my hw

Answer 40

let me check it

Answer 41

its n alright

Answer 42

what happen to your second power

Answer 43

do you own a graphing calculator?

Answer 44

i realized what i did worng it would be (x-3)^2=5
then u would have to bring the 5 over and multiply it by 2 wih the final answer being y=2(x-3)^2-10.
yes i do

Answer 45

yes you are correct now

Answer 46

do you know how to find the vertex with it? It is a TI

Answer 47

of this problem or the previous one? its TI-84

Answer 48

either one
put your equation into y= screen
graph it