## Thursday, May 7, 2015

### 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}→L
{1,1,1,1}→L
Goto 0
Lbl 1
0→K
Repeat K=105
getKey→K
If K=92:Then
L(1)+1→L(1)
If L(1)=5:1→L(1)
Circle(–5,5,4,L(L(1)))
End
If K=93:Then
L(2)+1→L(2)
If L(2)=5:1→L(2)
Circle(5,5,4,L(L(2)))
End
If K=94:Then
L(3)+1→L(3)
If L(3)=5:1→L(3)
Circle(–5,–5,4,L(L(3)))
End
If K=82:Then
L(4)+1→L(4)
If L(4)=5:1→L(4)
Circle(5,–5,4,L(L(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
Lbl 2
Input "Y, USE STRINGS:",Y
Lbl 1
GraphColor(1,BLACK)
Input "LOW:",A
Input "HIGH:",B
fnInt(√(1+nDeriv(Y,X,X)²),X,A,B)→L
Disp "ARC LENGTH=",L
Pause
For(K,A,B,ΔX)
Pt-On(K,Y(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:
FnOn 1:FnOn 2
Lbl 2
Input "Y:",Y
Input "Y:",Y
Lbl 1
GraphColor(1,BLACK)
GraphColor(2,BLUE)
solve(Y-Y,X,Xmin)→A
solve(Y-Y,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 Y(C)≥Y(C):Then
fnInt(Y-Y,X,A,B)→I
Disp "AREA=",I
Disp "PRESS ENTER TO GRAPH"
Pause
Else
fnInt(Y-Y,X,A,B)→I
Disp "AREA=",I
Pause
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.

1. How do the 84 drop progarms work can u tell me how so I know what to do with those dorps plz thank u

2. How do the 84 drop progarms work can u tell me how so I know what to do with those dorps plz thank u

1. Donta,

Can you elaborate about the drop programs please? Thanks,

Eddie

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