выч методы не разобраны! / LAB2-И~1 / 2ЛАБА~1 / INTEGRAL / INT___

Program Integral;
uses crt;
const eps=0.001;
x0=0;
xn=3;
t=0.57735; {1/sqrt(3)}
var x1,x2, Int, h, a, b:real;

function f(_x_:real):real;
begin
f:=sqr(_x_)/(sqr(1-sqr(sqr(_x_))*_x_)*(1-sqr(sqr(_x_))*_x_)+2);
end;

function epsi(a,b:real):real;
var h, f4:real;
begin
h:=(b-a)/4;
f4:=(f(b)-4*f(b-h)+6*f(b-2*h)-4*f(b-3*h)+f(a))/(sqr(sqr(h)));
epsi:=1/11520*sqr(sqr(b-a))*(b-a)*f4;
end;

begin
clrscr;
a:=x0; b:=xn;
Int:=0;
while abs(a-b)>=0.00001 do
begin if abs(epsi(a,b))<=eps*(b-a)/(xn-x0) then
begin
write('[',a:0:3,',',b:0:3,'] ');
x1:=(b+a)/2-(b-a)/2*t;
x2:=(b+a)/2+(b-a)/2*t;
Int:=Int+1.5*(f(x1)+f(x2));
write(Int:0:6,' ');
write(epsi(a,b):0:6,' ');
write(eps*(b-a)/(xn-x0):0:6);
writeln;
a:=b; b:=xn;
end
else b:=(a+b)/2;
end;
writeln(Int:0:6);
readln;
end.