TI-83+ solve equations?

[Foppah]

Is there any good program for TI83+ that solves equation?

Like this one:
3,5x = 5 + (x/6)

Or this one:
x^2-x-5=1

[DarkerLine]

Go to the math menu and press [0] (zero).

[Foppah]

Go to the math menu and press [0] (zero).

Oh... thank you.
But how do I enter this: 3,5x = 5 + (x/6)

[DarkerLine]

subtract one side from the other and set THAT equal to 0. If 0 = rhs - lhs, then it follows that lhs = rhs.

[Treefrog]

I'll upload my program to ticalc, just in case the Solve function doesn't suit your fancy.

[DarkerLine]

Code: Select all

ClrHome
Input "",Str1
ClrHome
Input Str1+"=",Str2
Input "X=",G
solve(expr(Str1)-expr(Str2),X,G

Solves an equation for X, just press [enter] where you want the equals sign to be.

[lecks]

omg ive always been looking for a program or something and ive always been thinking " why dont these darn calculators solve equations with unknown variables?" i wanted to smash texas instruments! a program likethis would be real nice

[Foppah]

Thank you all. Works great!

3,5x = 5 + (x/6) =

0 = 5 + (x/6) -3,5x

Solve says that x is 1.5 and that's correct! Im going to read my manual about this solve command, it's great.

[lecks]

i still dont understand this solver.. is there a program where you don't have to change around the equation to make it work? ive read my manual and its still very complicated, id rather work it out manually than do all that. a program that just does it would be real nice. is there any?

[Foppah]

i still dont understand this solver.. is there a program where you don't have to change around the equation to make it work? ive read my manual and its still very complicated, id rather work it out manually than do all that. a program that just does it would be real nice. is there any?

It's esay to use. Press ALPHA solve (enter) in APPS solve program to get the answer.

But how do i write this one?
x^2-x-5=1

I did try this one:
x^2-x-5-1=0

But it has x1 and x2 answers..... i get 3 for x1, but i wan't both answers.. should i change the value in "bound" or what? maybe i should change - for + ?

[lecks]

no matter what i put in it equals 0.. both on the solver and by hitting [alpha] [enter]

[Timendus]

I did try this one:
x^2-x-5-1=0

But it has x1 and x2 answers..... i get 3 for x1, but i wan't both answers.. should i change the value in "bound" or what? maybe i should change - for + ?

I suck at math, but I do know that you have to rewrite that to:

x^2-x-6=0
(1*x^2) + (-1*x) + (-6) = 0

Now, use the quadratic formula with A = 1, B = -1, C = -6
This gives the answers 3 and -2.

[Foppah]

I did try this one:
x^2-x-5-1=0

But it has x1 and x2 answers..... i get 3 for x1, but i wan't both answers.. should i change the value in "bound" or what? maybe i should change - for + ?

I suck at math, but I do know that you have to rewrite that to:

x^2-x-6=0
(1*x^2) + (-1*x) + (-6) = 0

Now, use the quadratic formula with A = 1, B = -1, C = -6
This gives the answers 3 and -2.

I solved it... I did enter x^2-x-5-1=0, then i got 3... then i change the X=value to -10 (like start search from it) and hit solve.. got -2.....

[benryves]

I did try this one:
x^2-x-5-1=0

But it has x1 and x2 answers..... i get 3 for x1, but i wan't both answers.. should i change the value in "bound" or what? maybe i should change - for + ?

I suck at math, but I do know that you have to rewrite that to:

x^2-x-6=0
(1*x^2) + (-1*x) + (-6) = 0

Now, use the quadratic formula with A = 1, B = -1, C = -6
This gives the answers 3 and -2.

Or just use a little factorising and turn x²-x-6=0 into (x-3)(x+2)=0 which also shows that x=3 or x=-2

[Timendus]

Ah, yes... I never had the insight to do that kind of things