Hi,
I've had this calculator for awhile, but I am trying to enter a full equation containing X, I know it turns into a quadratic and spits out 2 values, but for some reason this is only spitting out 1 value when I am using the Solver function, can anyone help?
The equation is:
(X)(X)/(.05-X)(.1-X) = 1.6
The only answer it is giving me is .363. I know there is another answer of .0367.
If anyone can help that'll be great!
Casio Fx-115es-algebra Equation Help
Started by
butters149
, Feb 28 2011 06:25 AM
1 reply to this topic
#2
JimC
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Calculators:
HP50g, TI-V200, TI-73, Casio FX-115ES, Casio FX-7400G Plus, Casio FX-7000G, Sharp EL-W516
Posted 01 March 2011 - 10:53 AM
The equation you give, (X)(X)/(.05-X)(.1-X) = 1.6
may be written as X^2 / ((.05-X)(.1-X)) = 1.6
and can be entered, just as you've done, on the fx-115ES.
You're correct, there are two solutions, (3 +/- 6) / 15 or approx 0.0367 and 0.363
When you type in your equation, and then launch the Solver by hitting {SHIFT}{CALC}, you'll notice that there is a number at the bottom of the screen. This is the Casio's initial guess for the Newton-Rapheson algorithm. You'll want to type in your own guesses at this point.
After you launch the Solver by pressing {SHIFT}{CALC}, try then typing {-}{5}{=} and you should get your first solution, 0.0367 or press {5}{=} to find your second solution 0.363 You will also see a screen asking for a dx? value which you can leave as is and just press {=} again. After your solutions are displayed, just press {=} again to rerun the Solver and try for another solution with a different initial guess.
The initial guess of -5 or +5 is arbitrary, just guesses and could be any widely spaced numbers.
The Solver can only find one solution at a time, and it will be the solution generally closer to the initial guess. The solver needs some guidance to find other solutions by changing the initial guess. If you're not sure where or how many solutions there are to your equation, the fx-115-ES does have a function table that you can run to get a rough idea of where all the possible solutions to your equation are located.
For more information, see my Scientific Calculator Comparison, which compares the operations of the Casio fx-115ES and the Sharp EL-W516. Hope this all helps!
JCullen
may be written as X^2 / ((.05-X)(.1-X)) = 1.6
and can be entered, just as you've done, on the fx-115ES.
You're correct, there are two solutions, (3 +/- 6) / 15 or approx 0.0367 and 0.363
When you type in your equation, and then launch the Solver by hitting {SHIFT}{CALC}, you'll notice that there is a number at the bottom of the screen. This is the Casio's initial guess for the Newton-Rapheson algorithm. You'll want to type in your own guesses at this point.
After you launch the Solver by pressing {SHIFT}{CALC}, try then typing {-}{5}{=} and you should get your first solution, 0.0367 or press {5}{=} to find your second solution 0.363 You will also see a screen asking for a dx? value which you can leave as is and just press {=} again. After your solutions are displayed, just press {=} again to rerun the Solver and try for another solution with a different initial guess.
The initial guess of -5 or +5 is arbitrary, just guesses and could be any widely spaced numbers.
The Solver can only find one solution at a time, and it will be the solution generally closer to the initial guess. The solver needs some guidance to find other solutions by changing the initial guess. If you're not sure where or how many solutions there are to your equation, the fx-115-ES does have a function table that you can run to get a rough idea of where all the possible solutions to your equation are located.
For more information, see my Scientific Calculator Comparison, which compares the operations of the Casio fx-115ES and the Sharp EL-W516. Hope this all helps!
JCullen
Hi,
I've had this calculator for awhile, but I am trying to enter a full equation containing X, I know it turns into a quadratic and spits out 2 values, but for some reason this is only spitting out 1 value when I am using the Solver function, can anyone help?
The equation is:
(X)(X)/(.05-X)(.1-X) = 1.6
The only answer it is giving me is .363. I know there is another answer of .0367.
If anyone can help that'll be great!
Edited by JimC, 01 March 2011 - 10:59 AM.
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