Question

I'm confused I don't even know where to start with this question help!
For the given quadratic equation convert into vertex form, find the vertex, and find
the value for x = 6. Show your work.
y = -2x2 + 2x +2

Answer 1

Well first you need to complete the square, do you know how to do that?

Answer 2

umm . I dont remember

Answer 3

first group the x terms together so you would have y= (-2x^2 +2x) +2

Answer 4

the take half of 2 in 2x and square and add it inside the parenthesis. so what do you get?

Answer 5

square it*

Answer 6

so if i half it then it would be 1 1/2^2?

Answer 7

it would just be 1 because half of 2 is 1 and then 1^2 is just 1

Answer 8

oh ok

Answer 9

so then it breaks up into x^2+2x+2 ?

Answer 10

no it would just be (-2x^2 + 2x +1) + 2

Answer 11

because you aren't familiar with completing the square we can use the formula -b/2a or we can stick to completing the square it's up to you

Answer 12

-b/2a is a little easier

Answer 13

ok sure show me please

Answer 14

okay so what represents b in the equation?

Answer 15

-2x^2

Answer 16

no, an example would be y=ax^2 + bx + c

Answer 17

only focus on the leading coefficient

Answer 18

well in this case not the leading coefficient but just the coefficients

Answer 19

so would the leading coefficient be -2? because it starts first?

Answer 20

sorry i told you the wrong thing that's my fault. it would just be 2

Answer 21

or just 2?
lol its ok thats what i was reading as well

Answer 22

okay so now -2 would be a. so using -b/2a, what would you get?

Answer 23

ok just so im understanding correctly when plugging it into the formula -b/2a it becomes 2/-2?

Answer 24

then the answer to that is -1

Answer 25

not quite. when you plug it in you would get -2/2(-2)
do you understand how i got that?

Answer 26

yes

Answer 27

we keep the same thingn in the formula

Answer 28

okay then when you simplify it you get 1/2

Answer 29

my responses arent being posted

Answer 30

hmm that's weird i see your responses though, maybe it's your computer?

Answer 31

but now you have x=1/2. i should've wrote the full formula but it's x=-b/2a so that's how i found x for the vertex, now all we need to find is y