Question

y=$left { {{ x^{2} } ,atop { sqrt{x} }}, right {{x leq 0} atop {x>0}} right.$  

Answer 1

var
  x, y: real;
begin
  readln(x);
  if (x <= 0) then
    y := sqr(x)
  else
    y := sqrt(x);
  writeln(y);
end.