一元二次方程求解.pas

一元二次方程求解

unit Unit22;

interface

 function  Equation1E2Power(a,b,c:extended;var X1,X2:extended):byte;
 //Result=0:方程无实根;Result=1:方程有一实根X1;Result=2:方程有两个实根

implementation

function  Equation1E2Power(a,b,c:extended;var X1,X2:extended):byte;
begin
 X1:=b*b-4*a*c;
 if X1<0 then
  begin
   Result:=0;
   X1:=0; X2:=0;
  end
 else if abs(X1)<EP then
  begin
   Result:=1;
   X1:=-b/(2*a); X2:=X1;
  end
 else
  begin
   Result:=2;
   X2:=(-b-sqrt(X1))/(2*a);
   X1:=(-b+sqrt(X1))/(2*a);
  end;
end;

end.