//[].

n=5000;



function y=f(x), y=cos(%pi*x)*sqrt(4-x^2); endfunction

function y=g(x), y=x^2*sqrt(4-x^2); endfunction

function y=h(x), y=x^4*sqrt(4-x^2); endfunction



F=[];
G=[];
H=[];
for i=1:n,
u=4*rand()-2;
F=[F,4*f(u)];
G=[G,4*g(u)];
H=[H,4*h(u)];
end

SF=sum(F)/n;
SG=sum(G)/n;
SH=sum(H)/n;

IF=integrate('f(x)','x',-2,2);
IG=integrate('g(x)','x',-2,2);
IH=integrate('h(x)','x',-2,2);


valeurs_exactes=[IF,IG,IH]
valeurs_approchees=[SF,SG,SH]