Question

Find the vertex of the parabola by completing the square.
x^2-6x+8=y
B. (3,-1)
C. (-3,1)
D.-(-1,3)

Answer 1

vertex of a parabola? u mean the axis of symmetry..?

Answer 2

No the vertex of a parabola is what it is on my test

Answer 3

why not u graph it on a graphic calculator? or u dont have 1..?

Answer 4

no i do not

Answer 5

just graph from -3<x<3

Answer 6

oh ok.. there is an easier way.. x = b/2a

Answer 7

that will get u ur x value for ur vertex

Answer 8

answer is A rite?

Answer 9

u want to know how i got the formula x = -b/2a?

Answer 10

do yu mean B because i didnt post A and yes please

Answer 11

umm yeah i meant B lol
ok.. u see when u graph the parabola from -3<x<3 u will see that its like a U shape or u could just graph y=x^2 on a paper then the shape of the graph is like a U that cuts the x axis and y axis at (0,0)

Answer 12

now when u differentiate the equation.. u learn differentiation alrdy rite?

Answer 13

No i havent

Answer 14

uh oh.. then thats not good.
i could give u a website it should explain well but i guess u can just memorize the formula x=-b/2a

Answer 15

yes.

Answer 16

or u can just learn the basics of differentiation on google i think u just take 10 mins to understand and u are ready to go

Answer 17

http://www.mathwarehouse.com/geometry/parabola/axis-of-symmetry.php

Answer 18

Alright thank you

Answer 19

no problem