can you put in a function on a graphing calculator that will allow you to go back and just change the variable

Question

i don't want to put in a long function every time, i just need to go back and change the variable

Answer 1

Hi,
Graphing calculators such as the TI-83 Plus/TI-84 series allow you to do that easily. Let's say we want f(x) = x² +3x +2 when x = 2, 3, 7.
a) Store the first value in x: 2, STO, (x,T,0,n), ENTER.
b) Enter the equation and press ENTER and you'll get the value for 2.
c) Store the second value in x: 3, STO, (x,T,0,n), ENTER.
d) Press 2ND, ENTER twice to display the equation again; then press ENTER to get the second evaluation.
f) Repeat step c with 7 and repeat step d for the new value.

FE

Answer 2

Yes, it's quite simple. First, enter the first value you want and store it into a variable. Type in the "equation" using that variable - this should be available on both scientific and graphing calculators - then hit "enter". Now you have the first value.

Here's the trick - hit the back button to return to the line you stored the variable. Change the variable. Run the equation again. Your next value is displayed.

Example: You want to evaluate f(x) = x + 1 at 1,2

1 -> X Store 1 into X
X+1 Type equation, hit enter
2 Displays output
1 -> X Return to store screen
2 -> X Change value
X+1 Return to equation screen
3 Hit enter, output is displayed.

Answer 3

That's what graphing calculators are for. Look in your operator's manual.