Program HelloWorld(output);
{$mode objFPC}
function degrees2radians(x: real) : real;
begin
result := x * 3.14159 / 180.0;
end;
function fun1(x: real) : real;
begin
result := Sin(degrees2radians(x));
end;
function rect_method(a: real; b: real; n: integer) : real;
var
h: real;
integral: real;
i : integer;
begin
integral := 0;
i := 0;
h := (a - b) / n;
writeln('h = ', h);
for i := 1 to n do
begin
writeln('fun1(b + i*h)*h = ', fun1(b + i*h)*h);
integral := integral + fun1(b + i*h)*h;
end;
writeln('integral = ', integral);
result := integral;
end;
var
result: real;
begin
result := rect_method(1.0, -2.0, 3);
writeln('result = ', result);
end.
