Euler's method on casio classpad?

[cameron_15]

Is there a way it can be done?

If not, heinneman want me to use the formula 20 times to find the 20th solution. I just cannot be bothered!

[ed_saifa]

It should be pre loaded in eActivity

[cameron_15]

It should be pre loaded in eActivity

can you elaborate on that a little more?..

can't seem to find it...

[Martoman]

Write your own.

[cameron_15]

figured out how to do it in the sequence section...

thanks for your help ed...

[supernatural]

so how do u do it on the classpad?

[_avO]

I'm assuming casio classpad is the touchscreen calculator
To make it easier ill use an example:

Solve the differential equation dy/dx = sec(x)^2, at x = 1, given y = 2 when x = 0, and a step size of 0.1 using the CAS spreadsheet

1) Go to Spreadsheet in Menu
2) Tap on A1, type in 0
    Tap on B1, type in 2
You can probably see that A1 and B1 are the given points, where A is the x value and B is the y value
3) The step size is 0.1, tap on A2 and type =A1+0.1 (make sure the = is there!), press EXE
4) Tap on A2 -> Edit -> Fill Range, you will see this
Formula [ =A1+0.1  ]
Range   [A2           ]
Change the Range to A2:A11 (because 0.01x10=1), you can find the : and A on the top row of the screen, tap OK
5) Tap on B2 and type =B1+0.1(1/(cos(A1)^2), as you would know secx^2 = 1/cosx^2. press EXE
6) Tap on B2 -> Edit -> Fill Range
Similarly to step 4, change the range to B2:B11, tap OK

Scroll down to where the A value is 1, the B value gives the corresponding y value (to the question asking for the y value when x=1)

[cameron_15]

I apologize for my inability to create subscript digits, I'm hope you guys can follow this (it's difficult for me to explain over the internet)

To do it on Cas, Bring up sequence mode from the main menu...

You'll see boxes for 3 variables, a, b and c.

For simplicity, I use 'a' as x values and 'b' for y values.


a(n+1) is the new x value, let this equal an + h

a0 is the initial x value

b(n+1) is the differential equation, enter this in terms of bn and an (these values are found in keyboard>math>OPTN)

b0 is initial y value




As an example. I want to find the range of values of the equation dy/dx=2x-1 with a step size of 0.1, initial conditions x=1 when y=2.

a0=1
b0=2
a(n+1)= an+.1
b(n+1)= 0.1(2an-1) +Bn    > that is h(2xn-1) + yn

from here, select the boxes for a and b, then click on the button that resembles an open book (can't describe it any other way) in the top menu bar. from their you can choose what results you want to bring up by pressing the button with the 2 arrows, x... and y... in it.


feel free to rewrite this better using fancy text etc if you want.

I also cannot take credit for this, as It was my classmate Keith who told me.  

I hope that made sense

[Richiie]

i think theres a demonstration on the essential book on how to do it.

[darkphoenix]

I think this was the program you were looking for.

Or get it from the original site, scroll down to the bottom:
http://www.casio.edu.shriro.com.au/cr_classpad_program.php

[samiira]

can u do it on the normal cas calculator aswell??..

[fady_22]

can u do it on the normal cas calculator aswell??..

You mean the TI-89?

There's a program here: http://math.arizona.edu/~krawczyk/Calculator/TI89/TI89NEul.html.
Just type it out in the Program Editor.
Works well, but you have to clear variables after you use it. (i.e. select NewProb in the F6 menu after using it).

It's probably best to save it in a folder other than the main one, so it does not affect your calculations.

[samiira]

nah the ti-nspire cas