c:/gdsf/web/fuentes_pascal/ecuacion

PROGRAM EJER59;
USES CRT;
VAR a, b, c, d, r1, r2, x, y : REAL;
BEGIN
CLRSCR;
WRITE ('Coeficiente a -> ');
READLN (a);
WRITE ('Coeficiente b -> ');
READLN (b);
WRITE ('Coeficiente c -> ');
READLN (c);
IF (a = 0) AND (b = 0) THEN
     BEGIN
     WRITE ('La ecuacion es degenerada');
     EXIT;
     END
ELSE
     IF (a = 0) AND (b <> 0) THEN
        BEGIN
        r1 := c / b;
        WRITE ('r1 = ');
        WRITELN (r1 : 5 : 2);
        EXIT;
        END
     ELSE
        BEGIN
        d := SQR (b) - 4 * a * c;
        IF (d >= 0) THEN
           BEGIN
           r1 := ( - b + SQRT (SQR (b) - 4 * a * c) ) / (2 * a);
           r2 := ( - b - SQRT (SQR (b) - 4 * a * c) ) / (2 * a);
           WRITE ('r1 = ');
           WRITELN (r1 : 5 : 2);
           WRITE ('r2 = ');
           WRITELN (r2 : 5 : 2);
           END
        ELSE
           BEGIN
           x := - b / (2 * a);
           y := - b - SQRT (ABS (SQR (b) - 4 * a * c) );
           WRITE ('r1 = ');
           WRITE (x : 5 : 2);
           WRITE (' + ');
           WRITE (y : 5 : 2);
           WRITELN ('i');
           WRITE ('r2 = ');
           WRITE (x : 5 : 2);
           WRITE (' - ');
           WRITE (y : 5 : 2);
           WRITELN ('i');
           END;
        END;
END.