graphing calculator

[raene zitkus]

i dont know if im at the right place, but i desperately need help with evaluating functions on my ti-84 calculator.....please, anyone...

 

[pka]

i dont know if im at the right place, but i desperately need help with evaluating functions on my ti-84 calculator.....please, anyone...

Well post a real question. What you posted is simply a statement.

 

[mmm4444bot]

Here is the latest TI-84 Guidebook.

Function evaluation is discussed in Chapter 7 (page 115).

 

[raene zitkus]

ouch. sorry. ive been to several sites and i have not gotten a response.

my question is in regards to not just evaluating functions (i purchased the "for dummies" book) but also technical support, i suppose.

i have the expression x^2 -3x + 5. i am to evaluate by using the calculator. i have been through the steps of inputting this expression in the proper place, meaning Y1...then vars then Y- vars and function. here is where i am suppose to be able to put in (5) and i am to get the answer. However, my cursor doesnt go beyond the initial Y1. again meaning, I cannot put in the (5) because i do not have that option. i have checked my stat plots, my format, window, etc....

if you could help me get beyond this temporary insanity, hopefully without sarcasm, you would be greatly appreciated. i am not in advanced math; i am not a traditional student; and i am extremely sensitive at this point.

sincerely,

raene (rainy)

 

[raene zitkus]

thank you sir, maam, but if i could self teach i would be an elite member such as yourself. i have the guidebook downloaded, ive read it. i still have a malfunction somewhere. thank you for your time and effort.

 

[mmm4444bot]

i have the expression x^2 -3x + 5. i am to evaluate by using the calculator. i have been through the steps of inputting this expression in the proper place, meaning Y1...then vars then Y- vars and function. here is where i am suppose to be able to put in (5) and i am to get the answer.

Okay -- you have been given the function f(X) = X^2 - 3X + 5. You have named f(X) in the TI-84 as Y1.

Now, if you are thinking that you can somehow enter Y1(5) from the home screen (or elsewhere) and have the TI-84 display 15, then perhaps you've been misinformed.

The TI-84 model does not have a Computer Algebra System (CAS) built-in. (The TI-89 model comes with a CAS.)

You may still use the methods described in Chapter 7. The table will display the value of Y1 when X = 5.

If you would like from the home screen to evaluate different outputs of function f -- that is, see different values of Y1 -- for various values of X, then you will need to first store a value to the variable X, followed by recalling variable Y1 to the home screen.

At the bottom of page 20, the Guidebook explains how to store 5 to X.

On page 21, various methods are described for recalling the value of Y1. It appears that you should use either the fourth or fifth method listed.


PS: Once you store a Real value to the variable X, it will remain in there until you store something else to X or reset the variable to have no value.

if you could help me get beyond this temporary insanity, hopefully without sarcasm, you would be greatly appreciated.

i am extremely sensitive

You have perceived sarcasm where there is none. Grow thicker skin. :cool:

 

[mmm4444bot]

if i could self teach i would be an elite member such as yourself

See? There is no sarcasm up there, either.

Are you taking a math course on-line?

 

[mmm4444bot]

i have the guidebook downloaded, ive read it. i still have a malfunction somewhere

Kindly cite the page(s) that you're looking at, as well as specifically listing the step(s) that are malfunctioning on your machine.

It's been a few years since I handled a TI-84; maybe I'm forgetting something. Senior moments, ya know.

 

[galactus]

I am not familiar with the 84, but I have an 83 Plus.

With it, all you have to do is store 5 in variable X. Then, as mmm said, type in X^2-3X+5 and it will return 15.

X is a 2nd function on the 83. You hit ALPHA STO to display X.

To store 5, or any other numerical value, in the variable X, hit 5 STO ALPHA STO ENTER

5 is now stored in X. Now type in the expression you're evaluating, hit enter, and the result is displayed.

As I said, this is with a TI83. Hopefully, the 84 is similar.