Quadratic Formula

Most of us know the Quadratic Formula and how to use it, but does anyone know where it came from?

I'm trying to Google, but not working well. D:

From what i remember from my 9th grade summer, I believe you can derive the quadratic formula from ax^2+bx+c. However, i have forgotten that as of now... I am assuming the quadratic equation is :

x=-b+ or - (sqrt(b^2 - 4ac))/ 2a

I'm a bit rusty, it's summer afterall and i haven't used this since the beginning of calculus ><"

Edit:
Did you mean where did it come from as in country/civilization? because i can't help you there...
But if you want to derive the formula, use the completing the square method on the equation
ax^2+bx+c

Sorry if i can't be of any more use =O

From what i remember from my 9th grade summer, I believe you can derive the quadratic formula from ax^2+bx+c. However, i have forgotten that as of now... I am assuming the quadratic equation is :

x=-b+ or - (sqrt(b^2 - 4ac))/ 2a

I'm a bit rusty, it's summer afterall and i haven't used this since the beginning of calculus ><"

Edit:
Did you mean where did it come from as in country/civilization? because i can't help you there...
But if you want to derive the formula, use the completing the square method on the equation
ax^2+bx+c

Sorry if i can't be of any more use =O

I meant how you connect the ax^2+bx+c=0 to the Formula. :/

Let's see if i can do this right...

ax^2+bx+c=0
x^2 + b/a x = -c/a divide by "a"
x^2 + b/a x + ((1/2)(b/a x))^2 = -c/a + ((1/2)(b/a x))^2 completing the square
x^2 + b/a x + b^2/4a^2 = -c/a + b^2/4a^2 simplified
(x^2 + b/2a )^2 = -c/a + b^2/4a^2 Into binomial form (completed square)

x+ b/2a = sqrt(-c/a + b^2/4a^2 ) square root both sides
x= - b/2a + or - sqrt(-c/a + b^2/4a^2 ) move b/a x to other side

x= - b/2a + or - sqrt((-c/a * 4a/4a) + b^2/4a^2 ) common denominator

x= - b/2a + or - (sqrt( b^2 -4ac))/2a simplified

x= (- b + or - sqrt(b^2 - 4ac))/2a simplify more = quadratic formula.

hopefully you can read this... sorry if it is totally incoherent. but i believe that is how it is done... good luck with this =)

here is a more clear answer to what you are looking for

http://www.sosmath.com/algebra/quadratic...rmula.html

I was going to post my answer but Worthyness has it right, ima make it easier for you guys



Nvm it works now

I was going to post my answer but Worthyness has it right, ima make it easier for you guys



Can someone teach me how to put these images? >_> someone please put it

You did it right, Fiel just spilled some Chinchilla Bathing Powder on the server so those tags don't work right.

Also, thanks for the picture, my eyes don't ache from reading this one. XD

x0xpriestx0x, sorry, didn't see your post 'till just now. D: Thanks for the link. <3

By the way I use a program called TexnicCenter, with a codifier called Miktex.

This is called LaTeX, there is a tutorial on how to use this in http://www.artofproblemsolving.com where it says LaTeX in the left.

Also, thanks for the picture, my eyes don't ache from reading this one. XD
<3

LOL sorry for that... i didn't know how to make it pretty

I had an account on AoPS a long time ago...

Does anyone know who first derived that formula?

I dont know certainly who did it, but I wouldnt doubt it would be the Egyptians. Or Euclid, Pythagoras, or Diophantus.

http://www.sosmath.com/algebra/factor/fac11/fac11.html

hope the link works...

that went way over my head ><