Quadratics....vertex form? wow plz help lol

hollerback1

Junior Member
Joined
Dec 21, 2005
Messages
80
Hello hollerback here, I'm just learned how to put the quadratics in vertex form...one problem. I DONT KNOW HOW TO DO IT :!: Please send me a link...explanation..what ever thanks guys.
 
If you mean "rearranging a quadratic so you can read the vertex off the equation", then the basic process is as follows:

. . . . .y = ax<sup>2</sup> + bx + c

. . . . .Factor out whatever is multiplied on the squared term,
. . . . .but factor it only from the variable terms.

. . . . .y = a[x<sup>2</sup> + (b/a)x] + c

. . . . .Take half of whatever is now multiplied on the linear
. . . . .("x") term, and square it. To "complete the square",
. . . . .you'll be adding this inside the brackets; to keep that
. . . . .side "even" (unchanged), you'll also be subtracting it
. . . . .from the same side.

. . . . .y = a[x<sup>2</sup> + (b/a)x + (b/2a)<sup>2</sup>] + c - a[(b/2a)<sup>2</sup>]

. . . . .Now convert to "complete the square" form:

. . . . .y = a[x + (b/2a)]<sup>2</sup> + c - (b<sup>2</sup>/4a)

Simplify, and read off the values for h and k.

Eliz.
 
Confused...

hmmm...I tried translating the equations, and I just don't get what to divide half by(/2) or to square. Please rephrase it again in a easier way for me if u can, thanks alot.

Back1 :wink:
 
TO gene

hey I looked over all the equations and i think the first one i need...but iam still confused on it.

y = a[x2 + (b/a)x] + c
 
Look at the site I posted or what Staple did. (They say the same thing.)
Start at
y = a[x^2 + (b/a)x] + c
And look at what happens with the multiplier of the x term, b/a.
It is what is divided by 2 then squared, added inside the bracket and subtracted outside.
y = a[x^2 + (b/a)x + (b/2a)^2] + c - a[(b/2a)^2]
 
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