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TI-84+ App4Calculus

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TheCoder1998:
hey guys,


i've made a great program for calculus using basicbuilder
omnicalc, symbolic and prettyprint are required for it to run
please check it out!

TheCoder1998:
well, it seems my program wasn't working properly so here's a new version of it
you can now calculate the volume of a solid of revolution and you can calculate double or triple integrals :D
oh and the function for partial fractions is removed (for now)

Aspiring:
Just tried it and it is outstanding!  :o Just one question.  How do you enter slope equations for slope fields I can't figure it out?

BTW, I used your program to calculate pi and it was able to find: 3.141587076 I think that is a pretty accurate approximation for a ti-84.  Do you have most of the rules for calculating derivatives in the app?  My calculus book has about 40 derivative formulas.  This app is super cool.  :thumbsup:

EDIT: hey I am a level 2 member now.  :)

TheCoder1998:
Thanks for the reply :D


when you want to input an equation for the slope fields, you get two choices,


one is for an implicit equation, like x^2+y^2=1, so you'll get the differential equation dy/dx=-x/y
the other is just for dy/dx (or y')


and yes, all derivative rules are in the app thanks to the symbolic function (but it won't simplify trig identities)


but now i've got yet another new version :D


oh and by the way, how exactly did you approximate pi?
i assume you used the taylor series function?

Aspiring:
Opps I knew dy/dx is y'.  I write down y' a bit too often I guess...

I found pi by using the arc length...
To approximate pi you take the equation of a circle and solve for y
x^2 + y^2 = R^2
y = +/- squareroot ( R^2 - X^2 )
We will just use the positive of the squareroot.
y =  squareroot ( R^2 - X^2 )
We know that the circumference of a circle = 2 * pi * r
So... pi = circumference / (2*r)
We will set r to 1 and taking only the positive solution of the squareroot gives half of the diameter.  Therefore...
pi is equal to the arc length of the half circle made by the equation: y = squareroot( 1 - x^2 ) :)
hope that makes sense.
Here's a link to wolfram alpha: https://www.wolframalpha.com/input/?i=integrate+%28++1%2B+%28+-x%2F%28%281-x^2%29^%281%2F2%29%29+%29^2++%29^%281%2F2%29+from+-1+to+1+with+1000+digits

EDIT: I used the partial fractions integration mode and it was like a miracle it solved it!  And it was really fast! Wow! I didn't think anything like this would ever show up on the ti-84 series  :thumbsup: (except really over priced ZoomMath  :( ).

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