equation.pas

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program equation(input,output);
const zero=1e-11;  {精度}
var a,b,x,fa,fx:real;
   m,n,p:integer;

function f(m,n,p,x:real):real;
  begin
    f:=exp(x*ln(m))+exp(x*ln(n))-exp(x*ln(p));
  end;

begin {main}
  assign(input,'equation.in');
  assign(output,'equation.out');
  reset(input);
  rewrite(output);
  readln(m,n,p,a,b);
  close(input);
  if f(m,n,p,a)*f(m,n,p,b)>0
then begin writeln('NO');close(output);halt end{这说明在[a,b]区间中无解。}
else
  repeat
        x:=(a+b)/2;
        fa:=f(m,n,p,a);{求a的函数}
        fx:=f(m,n,p,x);{求b的函数}
        if fa*fx<0 then b:=x     {在[a,x]内有解}
                   else a:=x;    {在[x,b]内有解}
      until (abs(b-a)<zero);
  writeln((a+b)/2);
  writeln(f(m,n,p,(a+b)/2));{输出解}
  close(output)
end.