Question

Calculate the amount of your simple interest investment after 10 years. Remember to use the same rate and compounding as in #1.
So my interesrt is .84% daily. and i already have 7500 in my account

Answer 1

@zepdrix

Answer 2

\[\Large I=Prt\]
Hmm I don't think simple interest has anything to do with compounding as we had in our compound interest problem. I wonder why they mentioned it here. hmm :o

Answer 3

\[\Large P=7500\]\[\Large r=.0084\]\[\Large t=10\]

\[\Large I=?\]
:D

Answer 4

630?

Answer 5

Mmmmmmm yah that sounds right :o

I'm not too familiar with the interest problems but I think that's all they wanted us to do for this one.

Answer 6

Thank you so much for helping me! yayy!

Answer 7

lol yer silly c:

Answer 8

OK ARE YOU UP FOR ONE MORE?"_

Answer 9

sure, just post it in this thread, it's not very long yet so shouldn't be a problem.

Answer 10

let me just send you a picture hold on

Answer 11

ok we are on number 3 :))))

Answer 12

Ooo fun graph tool :O look at all the buttons!

Answer 13

ahahhahhaaahah! i just laughed so hard hahahaha your so silly!

Answer 14

sure, just post it in this thread, it's not very long yet so shouldn't be a problem.

Answer 15

Ooo fun graph tool :O look at all the buttons!

Answer 16

So let's graphing the Simple Interest first since that will be easier.

We'll graph `time` in the horizontal direction (the x direction),
and `cash monies` in the vertical direction (the y direction).

Answer 17

So this is where we'll want to go back to using a ton of brackets so our answer will be ACCURATE.

Answer 18

Recall after we plugged in all of our jimmy jammies we had,\[\Large A=7500\left(1+\frac{.0084}{365}\right)^{365*10}\]
But what we want to do now is, we DON'T want to plug in the `t` value.
We want to allow our `t` to vary.Recall after we plugged in all of our jimmy jammies we had,\[\Large A=7500\left(1+\frac{.0084}{365}\right)^{365*t}\]

Answer 19

Blah fail copy paste.. my bad.

Answer 20

So that function we have there... we want to write it using brackets and stuff so the program will graph it.

Answer 21

woah woah woah what? i have no idea what your talking about :(

Answer 22

You remember this?\[\Large A=7500\left(1+\frac{.0084}{365}\right)^{365*10}\]

Answer 23

and here is the link to the graph thing. http://www.geogebra.org/cms/en/

Answer 24

There's a chrome app? oo very cool

Answer 25

and yes i do remember that equation

Answer 26

\[\Large A=7500\left(1+\frac{.0084}{365}\right)^{365*\color{#F35633}{10}}\]
The 10 is there because the problem told us to \(\Large t=10\).
We want to undo plugging that 10 in giving us this now.\[\Large A=7500\left(1+\frac{.0084}{365}\right)^{365*\color{#F35633}{t}}\]k? :o

Answer 27

ok! and what does this have to do with the graphing though???

Answer 28

The amount of cash money we can make, \(\Large A\) is related to the amount of time, \(\Large t\), we allow to pass.
So we can show how our money relates to time by graphing a line, or curve in this case.

Answer 29

Ah crap, I said we were going to start with `Simple Interest` didn't I? Grr

Answer 30

Ok ok let's switch to the Simple Interest Formula a sec.

Answer 31

\[\Large I=Prt \qquad\to\qquad I=7500*.0084*\color{#F35633}{10}\]Again, we want to undo plugging in the 10.\[\Large I=7500*.0084*\color{#F35633}{t}\]

Answer 32

The graphing utility will only allow us to graph in x and y.
So remember what I mentioned earlier.

We'll graph time in the horizontal direction (as x),
and Interest in the vertical direction (as y).

Answer 33

\[\Large y=7500*.0084*x\]
Understand? D: A little bit maybe?

Answer 34

Uh oh :c your head esplode?

Answer 35

no no no i understand!

Answer 36

@zepdrix ?

Answer 37

So at the bottom of the graphing utility, there is a space to type in your function.

Answer 38

Did you try graphing it yet? :o

Answer 39

what do i graph?

Answer 40

ugh this is so frustrating!

Answer 41

This is our simplie interest formula, graph this, \[\Large y=7500*.0084*x\]

Answer 42

in x?

Answer 43

I changed \(\Large I\) to \(\Large y\),
and \(\Large t\) to \(\Large x\).
That allows us to graph this in \(\large x\) and \(\Large y\).

Answer 44

so 7500 * . 0084 * x is for the Y axis?

Answer 45

yes,
x is for the x axis.
7500*.0084*x is for the y axis.

Answer 46

You see the `input` box at the bottom, right? :o

Answer 47

yes and i entered it in there

Answer 48

and this is what it looks like

Answer 49

is this correct?

Answer 50

Yes.
So you see that tiny sliver?
It's a line with a really really big slope.
So it's growing really quickly.

Answer 51

The other one will be a tad harder to type into our input box.
We'll have to be careful with the brackets we use.\[\Large A=7500\left(1+\frac{.0084}{365}\right)^{365t}\]
In x and y this becomes,\[\Large y=7500\left(1+\frac{.0084}{365}\right)^{365x}\]

Answer 52

We'll want to input it like this,\[\Large y=7500(1+(.0084/365))\wedge(365x)\]

Answer 53

Hmm it's not accepting it.. lemme see what's going on -_-

Answer 54

ok:(

Answer 55

Mmm ok I guess we don't want to use that many brackets.

put this into the input box:
7500(1+.0084/365)^(365x)

Answer 56

You'll have to zoom way way out in order to actually see the line.

Answer 57

ok lets seeee....

Answer 58

how do i zoom?

Answer 59

Do you have a scroll wheel on your mouse? :)
Are you using a mouse? hehe

Answer 60

no im on a laptop

Answer 61

Go to the last icon on the top bar, which looks like a cross with arrows on the end.
Click the white arrow under it for a drop down menu, there should be a zoom out option.

Answer 62

even when i zoom in i cant see it :(

Answer 63

zoom out! :O

Answer 64

does your look like this?

Answer 65

yesss good good

Answer 66

So hopefully we're doing this right +_+ lol

Answer 67

Mmm crap hold on....

Answer 68

i know right haha now what?

Answer 69

Ohhh Ok ok ok ok ok ok ok ok

Answer 70

Check back on your first problem page.
See below the input example, the message:
`Notice that A= was not included, that 10 was used instead of 10,000 (because this graph is scaled in thousands),`

Answer 71

I think they want us to scale this like they did in the example.
Hmm

Answer 72

It will look a lot nicer when we graph it.

Answer 73

how do we do that?

Answer 74

Ummmmmmmmmm

Answer 75

hahah i thought so too!

Answer 76

I guess we could use the same scale they did in the example.
So we would divide our `Principle` value by 10,000.

Err no, 1000 scale would make more sense maybe.... grrrr

Answer 77

what should i do then??

Answer 78

Dividing our principal value by 1000 gives us,
P=7500/1000 --> P=7.5

So we would instead want to graph:
7.5(1+.0084/365)^(365x)

and

7.5*.0084x

Answer 79

They look a little bit better I guess.
I dunno.. the instructions are confusing for this question >:C

Answer 80

You'll have to zoom OUT a bit to get the nice shape.
It will look better than the previous one did though.

Answer 81

i got it!but how come it doesnt look like the one in the example?

Answer 82

What example ? :o

Answer 83

the one that i linked to you? ill show it again hold on

Answer 84

There is no line graphed in that picture..
You mean the way the graph layout looks?

Answer 85

yes! idk is it suppossed to look like the example?

Answer 86

Mmm there was a button to add a `grid` .. i'm trying to remember where it was at.

Answer 87

I guess you can right click on the graph, `show grid`

Answer 88

That will make it look a bit similar :o

Answer 89

where is that at?

Answer 90

right click your mousey button on the graph. a menu will pop up

Answer 91

oh ok! now what do i do?

Answer 92

You can label the axes like they did in the example, if you want.
Something like this, but not stupid lol.

Answer 93

That's probably not necessary though :o lol

Answer 94

you are online school or something?