TI 84 Color Programs: Circles, Arc Length, Area Between Curves

TI 84 Color Programs

For this blog entry, I used TI Connect CE to transfer the programs and get screen shots.  It is sweet!  TI Connect CE works with the TI-84 Plus family (Monochrome, C Silver Edition, and the upcoming CE (review coming soon!)).  You can edit programs and transfer them.  The interface is a lot nicer, and you can drag and drop programs and data files. 

This blog will feature some of the color functions and commands of the TI 84 Plus C Silver Edition (and the upcoming TI 84 Plus CE). 

CIRCLE4 in Progress

CIRCLE4:  Circle Draw and Update Program

Notes:

*  Press 1, 2, 3, and 4 to change the color of the circles.  The colors cycle through black, blue, red, and green.

*  Since a list is used, we must use the numeric color identifiers: 12 for black, 10 for blue, 11 for red, and 14 for Green. (see table below for full reference)

* Database is stored and recalled to preserve the current database (0).

Numeric Color Identifiers:

10:  blue

11:  red

12:  black

13:  magenta

14:  green

15:  orange

16:  brown

17:  navy

18:  light blue

19:  yellow

20:  white

21:  light gray

22:  medium gray

23:  gray

24:  dark gray

Program:

StoreGDB 0:0→J

AxesOff:FnOff

ZStandard:ClrDraw

{12,10,11,14}→L₅

{1,1,1,1}→L₆

Goto 0

Lbl 1

0→K

Repeat K=105

getKey→K

If K=92:Then

L₆(1)+1→L₆(1)

If L₆(1)=5:1→L₆(1)

Circle(–5,5,4,L₅(L₆(1)))

End

If K=93:Then

L₆(2)+1→L₆(2)

If L₆(2)=5:1→L₆(2)

Circle(5,5,4,L₅(L₆(2)))

End

If K=94:Then

L₆(3)+1→L₆(3)

If L₆(3)=5:1→L₆(3)

Circle(–5,–5,4,L₅(L₆(3)))

End

If K=82:Then

L₆(4)+1→L₆(4)

If L₆(4)=5:1→L₆(4)

Circle(5,–5,4,L₅(L₆(4)))

End

End

RecallGDB 0

AxesOn

Stop

Lbl 0

Circle(–5,5,4,12)

Circle(5,5,4,12)

Circle(–5,–5,4,12)

Circle(5,–5,4,12)

Goto 1

ARC84C:  Arc Length

Find the Arc Length of function Y₁.  Once the arc length is calculated, the function is plotted in black and the arc length is plotted in red. 

Program:

FnOff :Func:FnOn 1

ClrDraw:Radian

Menu("USE Y₁?","YES",1,"NO",2)

Lbl 2

Input "Y₁, USE STRINGS:",Y₁

Lbl 1

GraphColor(1,BLACK)

Input "LOW:",A

Input "HIGH:",B

fnInt(√(1+nDeriv(Y₁,X,X)²),X,A,B)→L

Disp "ARC LENGTH=",L

Pause

For(K,A,B,ΔX)

Pt-On(K,Y₁(K),1,RED)

End

TextColor(BLUE)

Text(150,0,"ARC=")

Text(150,40,L)

Examples

Y₁ = cos(X)*e^X from X = 1 to 2.   Arc Length = 4.7031139029…

Y₁ = -2X^2 + 4X + 1 rom X = -2 to 2.   Arc Length = 20.7833…

AREABTWN:  Area Between Curves

This calculates the area between two curves, Y₁ and Y₂.  This program works best if you can set the graph screen to where the curves intersect at only two points.  The program first searches for two intersections, one from the left side of the graph screen (Xmin) and one from the right (Xmax).  After the area is calculated, both curves are graphed and the area between curves are shaded.  Function and Radian modes are used.

Program:

Func:Radian:FnOff :ClrDraw

FnOn 1:FnOn 2

Menu("USE Y₁/Y₂?","YES",1,"NO",2)

Lbl 2

Input "Y₁:",Y₁

Input "Y₂:",Y₂

Lbl 1

GraphColor(1,BLACK)

GraphColor(2,BLUE)

solve(Y₁-Y₂,X,Xmin)→A

solve(Y₁-Y₂,X,Xmax)→B

If A>B:Then

A→C:B→A:C→B:End

(A+B)/2→C

If A=B:Then

Disp "NO SOLUTION":Stop

End

If Y₁(C)≥Y₂(C):Then

fnInt(Y₁-Y₂,X,A,B)→I

Disp "AREA=",I

Disp "PRESS ENTER TO GRAPH"

Pause

Shade(Y₂,Y₁,A,B,1,1,GREEN)

Else

fnInt(Y₂-Y₁,X,A,B)→I

Disp "AREA=",I

Pause

Shade(Y₁,Y₂,A,B,1,1,GREEN)

End

Examples

The Standard Window is used.  Xmin = -10, Xmax = 10, Ymin = -10, Ymax = 10

Y₁ = -2X^2 + 4X + 1, Y₂ = X^2.   Area = 2.734721…

Y₁ = 1.2X + .63, Y₂ = -X^2 + 5X + 1.   Area = 10.58676675…

I plan to accomplish the same programs for the Casio Prizm soon.    Eddie

This blog is property of Edward Shore.  2015.