Anyone know how to do quadratic eqns (x^2 + x + 3) in a TI 83+? If so, please let me know. I'm trying to cut down time in doing the quadratic eqn. Thanks.

9/20/2005 9:56:51 PM

by do quadratic equations i take it you mean solve quadratic equations? in that case, i'd recommend using the solve function.

if memory serves correct, you would do something like

solve(x^2+x+3,x)

9/20/2005 10:01:57 PM

don't you have to use matrices with the 83+?

9/20/2005 10:02:02 PM

Write a quick program.

9/20/2005 10:03:55 PM

9/20/2005 10:37:05 PM

PROGRAM: QUADTRATI
: Disp "ax^2+bx+c=0"
: Disp "ENTER VALUES"
: Prompt A
: Prompt B
: Prompt C
: Disp (-B+(B^2-4*A*C)^.5)/(2*A)
: Disp (-B-(B^2-4*A*C)^.5)/(2*A)

9/20/2005 11:30:44 PM

gg with your TI-Basic programming

9/20/2005 11:31:39 PM

^^ almost 29k!

9/20/2005 11:38:49 PM

Thanks for the suggestions. I'm spending too much time trying to figure this out instead of studying.

9/20/2005 11:40:41 PM

I thought only the 89's and up had the solve function??

9/21/2005 12:06:29 PM

i have the T-86 and it has a Solver...

9/21/2005 12:15:12 PM

not sure about the 83+, but the 86 has a 'poly' function that solves any order polynomial. you just plug in the coefficients. so you could use that or the solver. 'poly' is the 2nd function on the 'prgm' button on my 86

9/21/2005 4:37:00 PM

i got the new 89 with usb, so i can do my programing on my computer, and i have the entire final fantasy 1 on there now, no more tank wars and nibbles for me

9/21/2005 6:19:27 PM

Copy the equation into the graph/plot section and then find hit the button the right of zoom (can't remember what it is called) and hit roots. It will give you the answers if they are real. If they are imaginary, you are out of luck.

9/21/2005 6:58:57 PM