I've completely forgotten the quadratic equation...

[AccruedExpenditure]

The quadratic equation *seemed* like such a big deal in 9th grade... almost like the fate of the world hung in the balance while you cranked out the solution. Now it's a forgotten artifact of grade school education gone the way of the Oregon trail and To Kill a Mockingbird...

I cry.
-N

 

[bignateyk]

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

im not actually sure if thats right or not... i havent used it in a few years.

 

[NatePo717]

Originally posted by: bignateyk
(-b+-sqrt(b^2-4ac))/2a

im not actually sure if thats right or not... i havent used it in a few years.

Close. it's a -b

 

[Aharami]

wow...same here

 

[krunchykrome]

Hahaha, my coworker just walked in and saw this thread on my screen. He looks at me and says "you computer geeks have nothing better to do than to talk about the quadratic equation?"

 

[WisMan]

Last semster my DIffyQ proffessor was like and to get the roots you can use the quadradic equation and half the class was like .

 

[Fourier Transform]

IF your equation is in the form ax^2 + bx + c = 0

The solutions are:

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

 

[Aharami]

damn. forgot Fourier and Laplace Transforms also. actually I've forgotten almost 95% of what I learned in my Comp Engg major.

only thing I remember are the girls I slept with and some moments here and there with my friends

 

[BrokenVisage]

Such an easy equation.. to forget!

 

[AccruedExpenditure]

Originally posted by: Aharami
damn. forgot Fourier and Laplace Transforms also. actually I've forgotten almost 95% of what I learned in my Comp Engg major.

only thing I remember are the girls I slept with and some moments here and there with my friends

:thumbsup:

 

[dullard]

Originally posted by: Fourier Transform
IF your equation is in the form ax^2 + bx + c = 0

The solutions are:

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

Why do people always over complicate it? Do a simple rewrite to make it like this:

If your equation is in the form ax^2 + x + c = 0
The solutions are:
x = [-1+-(1-4ac)^0.5] / 2a

No need for this silly 'b' term or taking the effort to square it.

 

[Fourier Transform]

Originally posted by: dullard

Originally posted by: Fourier Transform
IF your equation is in the form ax^2 + bx + c = 0

The solutions are:

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

Why do people always over complicate it? Do a simple rewrite to make it like this:

If your equation is in the form ax^2 + x + c = 0
The solutions are:
x = [-1+-(1-4ac)^0.5] / 2a

No need for this silly 'b' term or taking the effort to square it.

They are both equivalent really. I just posted the most common general form that's found.

 

[theeedude]

You should never forget your roots

 

[dullard]

Originally posted by: Fourier Transform
They are both equivalent really. I just posted the most common general form that's found.

Yes, but the most common general form is the most complicated with the most effort. I wouldn't teach it that way myself.

 

[Apathetic]

Uhh.. raising n to the 0.5 power *IS* taking the square root of n.

Dave

Originally posted by: dullard

Originally posted by: Fourier Transform
IF your equation is in the form ax^2 + bx + c = 0

The solutions are:

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

Why do people always over complicate it? Do a simple rewrite to make it like this:

If your equation is in the form ax^2 + x + c = 0
The solutions are:
x = [-1+-(1-4ac)^0.5] / 2a

No need for this silly 'b' term or taking the effort to square it.

 

[dullard]

Originally posted by: Apathetic
Uhh.. raising n to the 0.5 power *IS* taking the square root of n.

I said, you don't have to square 'b' for the b^2 part of the equation. You still have to take the square root. Two different things.

What I said above is the format that I've used ever since I learned the quadratic equation. Memorizing all of those terms was too much (was it -b, -a, -c to start with, is it a^2, b^2, c^2, etc.) so I simplified it myself and have been using the simplified version ever since. The simplification is less math work (ones are easy to work with) and less memorization work.

However, now that nearly 20 years have passed, I may change it one step better. The quadratic equation should be written in this form:

If your equation is in the form x = ax^2+c
The solutions are:
x = [1+-(1-4ac)^0.5] / 2a

The reason for this minor change is to address the problem bignateyk highlighted. He forgot to make the first 'b' term negative. So, I rewrote it to make it positive! One less problem to ever worry about.