Quadratic Formula for the TI-83 and 84

   Have you ever wondered if there is a way to make your calculator solve quadratic equations for you?  Well, there is a fairly easy way to make your calculator do all the work for you.

Another program that I have put on Instructables is Heron's Formula.
www.instructables.com/id/Herons-Formula-program-for-the-TI-83-and-84/

Step 1 Getting started

   You should know that a quadratic equation looks something like this: x^2-3x+2=0 or ax^2+bx+c=0.  This will be important later on.
The first step is to press the program button on your calculator.  Press the right arrow twice to get to new and select create new.  Enter a name. 
   Now press program again and press the right arrow then press 2. To get letters, push the alhpa button.  Now enter A,B,C and hit enter.

Comments

[MicheVonWitch]

hi. when you're putting in the numbers into the program, and say the equation is 12^2+x^2 =13^2 , how do we arrange it, and do we insert the power of the exponent into the program as well? thank you!

[Scout Jinx]

Sorry about getting back to you almost five months later... :)
I assume you are using this equation for the Pythagorean Theorem. If so, don’t use the program and just type in √(13²-12²)
If necessary write the ± symbol before your answer (*cough*5*cough*)

[lililijason]

Hi... First i have to thanks you for posting such a awesome program onto the internet.. i followed all the instructions but i found out that the answers came out are slightly different from the correct answer. The negative and positive signs of the 2 answers have been swapped. I want to know it's my problem with my program or.. the error of the program? (i check several times)

[Scout Jinx]

Make sure you put the parenthesis and commas in the right spot.  I might be of more help if I saw a picture or something of it.

[Klaudiuszm]

i made same program except with the works. was the first program i made just by looking off the source on my teachers calc.

[sjoobbani]

 Thank you.

[Scout Jinx]

Your welcome!

[valhallas_end]

Heh...its funny.  After years of math in college and engineering classes, this has always been the first formula I've programmed into every calculator I've owned. 

[Scout Jinx]

I wanted to let everyone know that I have made some changes to the program as of Feb 12, 2010.  This is just a minor change but it might affect your results.  Instead of having .../2A I changed it to /(2A).  If you have already written the program you might want to change it.  I changed the picture in step 3 accordingly.

[adityasingh]

Thanks so much. I really appreciate it!
Good job on the guide!

[error32]

You might want to display the result of (B^2-4AC) as this determines the results. if it's >0 the results are real, if it's 0 then the two results are the same and if it's < 0 the results are complex (you can display the answers by selecting "a+bi" in the [Mode] menu

[Futience]

Thnx!!! I really like this one, very handy for school :P. nice tut.

[SWSOE]

Nice tutorial. I wrote my own program to do this a while back which implements a command included with the OmniCalc application.  It will take the square root of a number and out the simplified version. Quite useful for displaying the answer in exact form when the answer is a never ending decimal. 

[gantyman]

i tried this and when when i put in the numbers it displays
"X=,X,Y
Done"
help!!!

[beta1072]

close the quotes after the equals sign