Question

Rewrite y = x2 + 4x + 5 in vertex form. Then find the vertex.

Answer 1

It's in standard form right now.... do you know vertex form?

Answer 2

\(\Large x^2 + 4x + 5=y\)
subtract 5 to both sides
\(\Large x^2 + 4x =y-5\)
take half of the coefficent and square, the coffeicent is 4x
\((\frac{4}{2})^2\)

Answer 3

-.- zale, you take the fun out of it

Answer 4

My bad :|

Answer 5

@bg5150 are you working on it? :o

Answer 6

sorry guys i had to run to the jon haha im gonna get on it

Answer 7

what does the vertex form look like?

Answer 8

is it the one you just posted?

Answer 9

No, vertex form is \(\Large y=(x-\color{red}h)^2+\color{blue} k\)

Answer 10

where h,k is the vertex of the parabola

Answer 11

what i suggested above was just the pathway of how to get the equation converted in vertex form.

Answer 12

ohhh i see

Answer 13

so lemme work this all out

Answer 14

Okay, thanks for participating :)

Answer 15

just use the complete the square method :P

Answer 16

wait dont confuse me now XD

Answer 17

Oh no, check this later after you have solved it on your own. Okay?

Answer 18

zale when i take the half and square it where does that go? im still new to all this XD

Answer 19

when you complete the square, you'd get 4
4/2=2
2^2=4
add and subtract 4 into the parenthesis and factor the (x^2+4x+4)
\(\large (x^2+4x+4)-4=y-5\)

Answer 20

\((x^2+4x+4)\) is in perfect trinomial, you know the factor for it?

Answer 21

(x+4)(x+1) i think

Answer 22

Perfect trinomial, meaning that (x+2)(x+2) is the factor, \((x+2)^2\).
\(\Large(x+2)^2-4=y-5\)

Answer 23

oh ok i see

Answer 24

What is the next step? We already have h
\(\Large (x-\color{red} h)^2+\color{blue}k=y\)
where h is -2
\(\Large(x-(\color{red}{-2}))^2-4=y-5\)
how do you get k?

Answer 25

add 5 to both sides?

Answer 26

yes

Answer 27

got it thank you so much!

Answer 28

Lol Zale is such a smarty pants. Good job :)

Answer 29

No problem, but you know why i got -2?
because we had (x+2)^2 and h is written in the vertex form as (x-h)^2
that means that 2 is negative \((x-(-2))^2\)

Answer 30

got it :) thanks zale

Answer 31

you're welcome~