PROGRAM pqform;
USES crt, graph;
VAR
a, b, c, x, x1, x2, d, y, g :real;
li, re, zx, zy, bildx, bildy, i :integer;
PROCEDURE init_g;
var
g0, g1 :integer;
begin
g0 := detect;
initgraph(g0, g1, 'BGI')
END;
PROCEDURE plott;
BEGIN
line(320,1,320,480);
line(1,240,640,240);
zx := 320;
zy := 240;
moveto(zx+li*50, round(zy-10*li*li+b*li+c));
li := li*100;
re := re*100;
setcolor(red);
FOR i := li TO re DO
BEGIN
x := i/100;
y := a*x*x+b*x+c;
bildx := round(zx+x*50);
bildy := round(zy-y*10);
lineto(round(bildx), round(bildy));
END;
END;
BEGIN
clrscr;
writeln('a:'); readln(a);
writeln('b:'); readln(b);
writeln('c:'); readln(c);
writeln('Untersuchungsbereich:'); readln(li); readln(re);
IF a = 0
THEN
IF b <> 0
THEN BEGIN
x := -(c/b);
writeln('x= ', x)
END
ELSE
IF c <> 0
THEN writeln('|L = { }')
ELSE BEGIN
writeln('|L = |R');
writeln('x= ', x);
END
ELSE
d := (b*b)/(4*a*a) -(c/a);
IF d > 0
THEN BEGIN
x1 := -(b/2) + sqrt(d);
x2 := -(b/2) - sqrt(d);
writeln('x1= ', x1);
writeln('x2= ', x2);
END
ELSE
IF d = 0
THEN
BEGIN
x := -b/2;
writeln('x = ', x);
END
ELSE
writeln('|L = { }');
readln;
init_g;
plott;
readln;
closegraph;
readln;
END.
