Quadratic Equation

I just realized I completely forgot this, does anybody know it. Thanks.

[felson]

Google is your friend.

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

ty

I will never forget that formula as long as I live.

Morphball...why in the hell did you need the quadratic equation may I ask?

A helpful way to remember it is to the tune of Pop Goes the Weasel.

"x equals negative b
plus or minus square root
of b squared minus four a c
all over 2a"

[ QUOTE ]
A helpful way to remember it is to the tune of Pop Goes the Weasel.

"x equals negative b
plus or minus square root
of b squared minus four a c
all over 2a"

[/ QUOTE ]

Coincidence?

If anyone needs me I'll be in my bomb shelter.

[chezlaw]

[ QUOTE ]
I just realized I completely forgot this, does anybody know it. Thanks.

[/ QUOTE ]
No need to remember, just complete the square.

ax^2 + bx + c = 0
x^2 + (b/a)x = -c/a
(x + (b/2a))^2 - b^2/4a^2 = -c/a [complete the square]
x + b/2a = sqrt(b^2/4a^2 - c/a)
tidy up and get [its tough typing this stuff]
x = ( -b +- sqrt(b^2 - 4ac) ) /2a

Strangly after years I can remember that with no trouble but cant remember the formula.

chez

I need it to calculate the trajectory of certain biological eruptions...you just can't go on with life unless you know, you know?

[soko]

solve(f(x),x)