Тест по информатике. 9 кл.

Var
    x1, x2, x3, x4, y1, y2, y3, y4: real;

function VectorLength(x1, y1, x2, y2: real): real;
begin
    VectorLength := sqrt(sqr(x1 - x2) + sqr(y1 - y2));
end;

function VectorSlope(x1, y1, x2, y2: real): real;
begin
    VectorSlope := (y1 - y2) / (x1 - x2);
end;

begin
    readln(x1, y1);
    readln(x2, y2);
    readln(x3, y3);
    readln(x4, y4);
    
    if (VectorLength(x1, y1, x2, y2) = VectorLength(x4, y4, x3, y3))
    and (VectorSlope(x1, y1, x2, y2) = VectorSlope(x4, y4, x3, y3)) then
        writeln('Yes')
    else writeln('No');
end.

//PascalABC.NET 3.1 сборка 1200
var
    a, b, c, d, x: real;
    x2: array[1..2]of real;
    i: integer;

begin
    readln(a, b, c);
    d := b * b - 4 * a * c;
    if d < 0 then begin
        writeln('Сложные комплексные корни');
        halt;
    end;
    
    d := sqrt(d);
    x2[1] := (-b + d) / 2 / a;
    x2[2] := (-b - d) / 2 / a;
    
    for i := 1 to 2 do
    begin
        x := sqrt(abs(x2[i]));
        if x2[i] >= 0 then
            writeln('x[', 2 * i - 1, '] = ', x, ' x[', 2 * i, '] = ', -x)
        else
            writeln('x[', 2 * i - 1, '] = ', x, 'i x[', 2 * i, '] = ', -x, 'i');
    end;
end.