GraphingCalculator 4;
Window 45 0 818 1396;
PaneDivider 395;
FontSizes 18;
BackgroundType 0;
SliderControlValue 0;
2D.Scale 1 0.25 5 1;
2D.BottomLeft -2.375 -42.875;
Text "Demonstration of the phenomenon of beats.  Non-dispersive medium.

Version 0.21, 4-10-13

V – wave speed; f, W, k <size=17>– frequency, angular frequency, wave number";
Color 2;
Expr V=1;
Color 3;
MathPaneSlider 10;
Expr f_1=slider([0,4,40]);
Color 4;
MathPaneSlider 10;
Expr f_2=slider([0,4,40]);
Color 5;
Expr W_1=2*pi*f_1,W_2=2*pi*f_2,k_1=W_1/V,k_2=W_2/V;
Text "<size=17>W – average frequency; 2B – beat frequency; A – amplitude";
Color 6;
Expr W=(W_2+W_1)/2,B=(W_2-W_1)/2;
Color 3;
Expr k=(k_2+k_1)/2,b=(k_2-k_1)/2;
Color 7;
Expr A=1;
Expr function(P_1,x)=A*cos([k_1*x-(W_1*n)]);
Color 8;
Expr function(P_2,x)=A*cos([k_2*x-(W_2*n)]);
Color 4;
Expr y=function(P_1,x);
Color 5;
Expr y=function(P_2,x);
Color 17;
Expr function(P_1,x)+function(P_2,x);
Text "<size=17>Oscillation & Envelope:	";
Color 17;
Expr 2*cos([b*x-(B*n)])*cos([k*x-(W*n)]);
Color 17;
Expr cos([k*x-(W*n)]);
Color 2;
Expr function(E,x)=2*cos([b*x-(B*n)]);
Color 17;
Expr function(E,x);
Color 17;
Expr -function(E,x);
Color 17;
Expr y^2=function(E,x)^2;
Text "<size=14>Author: David A. Craig <<http://web.lemoyne.edu/~craigda/>";