Question

how do you type the infinity sign on a graphing calculator ?

Answer 1

1E99

Answer 2

i just write it out ?

Answer 3

it says error

Answer 4

thats calculator for: 1x10^(99)

Answer 5

which model

Answer 6

TI - 84 plus

Answer 7

your comma button has an EE atop it, shift to get it

Answer 8

oh i see it now , hold up

Answer 9

Do you have a TI-89? These bad boys have an infinity BUTTON!! :D

Answer 10

oh no i have a 84 /:

Answer 11

lol @austinL

Answer 12

ti84 is the most ill go ... after that they started having to have terabytes for the instruction manuals and i gave up :)

Answer 13

@amistre64 it says EE but you said it was IE99

Answer 14

Same thing :)

Answer 15

it not my fault they cant type lol

Answer 16

Button likely says EE, but on screen it should say E

Answer 17

ok lemme try

Answer 18

the output on the screen is still:

one: 1
2nd, , : E
99: 99

Answer 19

is it a one or an I ?

Answer 20

they might have done that to distinguish it fromthe alpha E key :/

Answer 21

an i is not a real numerical value

Answer 22

"Imaginary"

Answer 23

i^k is one of 4 values ...

why are you needing an infinity?

Answer 24

Find the sum of the infinite geometric series, if possible. Show steps, if possible.
\sum_{{j}={1}}^{\infty}4 \cdot 0.5^{j-1}

Answer 25

hold up

Answer 26

\[\sum_{{j}={1}}^{\infty}4 \cdot 0.5^{j-1}\]

Answer 27

\[\sum_{{j}={1}}^{\infty}4 \cdot 0.5^{j-1}\]
\[\sum_{{j}={1}}^{\infty}4 \cdot 0.5^{j}~.5^{-1}\]
\[\frac{4}{.5}\sum_{{j}={1}}^{\infty}0.5^{j}\]

Answer 28

aha now what ? lol

Answer 29

is .5 less than 1?

Answer 30

theres a formula for this ....

Answer 31

yes

Answer 32

whats the formula ? im sorry my teacher doesnt give me all this info /:

Answer 33

\[\frac{1-r^k}{1-r}\]
if r < 1, then the limit as k to infinity is
\[\frac{1}{1-r}\]

Answer 34

whats r though ? the common ratio ?

Answer 35

but would it be possible to find the sum ?

Answer 36

let me rechk my thought tho ...

S = r + r^2 + r^3 + ... + r^n
-rS = - r^2 - r^3 - ... - r^n - r^(n+1)
-----------------------------------
(1-r)S = r + 0 ..........................- r^(n+1)

S= r - r^(n+1)
-----------
1 - r

Answer 37

if r < 1 then that exponented part goes to 0 leaving us:

S = r/(1-r) for the sum

Answer 38

might be better stated the |r| < 1, but why nitpick

Answer 39

\[\frac{4}{.5}\sum_{{j}={1}}^{\infty}0.5^{j}\]
\[\frac{4}{.5}~\frac{.5}{1-.5}\]
\[\frac{4}{.5}=8\]

Answer 40

http://www.wolframalpha.com/input/?i=sum+4%28.5%29%5E%28n-1%29%2C+n%3D1+to+inf

Answer 41

thanks soooo much !

Answer 42

youre welcome, as far as i know the ti84 does not have an infinite sum function

Answer 43

yes im aware haha