> restart;

> f1:=x-> 8/(Pi^2)*(cos(Pi*x/2)):

> f2:=x-> 8/(Pi^2)*(cos(Pi*x/2)+1/9*cos(3*Pi*x/2)):

> f3:=x-> 8/(Pi^2)*(cos(Pi*x/2)+1/9*cos(3*Pi*x/2)+1/25*cos(5*Pi*x/2)):

> f4:=x-> 8/(Pi^2)*(cos(Pi*x/2)+1/9*cos(3*Pi*x/2)+1/25*cos(5*Pi*x/2)+1/49*cos(7*Pi*x/2)):

> h:= x-> piecewise(-2<x and x<0,1+x,0<x and x<2,1-x):

> plot(h(x), x=-1.999..1.999, title = "Example 2", color = black);

> plot([h(x),f1(x)], x=-1.999..1.999, title = "Example 2, f(x), f1(x)", color = [black,black]);

> plot([h(x),f2(x)], x=-1.999..1.999, title = "Example 2, f(x), f2(x)", color = [black,black]);

> plot([h(x),f3(x)], x=-1.999..1.999, title = "Example 2, f(x), f3(x)", color = [black,black]);

> plot([h(x),f4(x)], x=-1.999..1.999, title = "Example 2, f(x), f4(x)", color = [black,black]);

> plot([f(x),f1(x),f4(x)], x=-10..10, title = "Example 2, Periodic extension", color = [black, black, black]);

>