/* ECP: FILEname=fig6_17.c */
/* 1*/   #include "root.h"

/* 2*/   int
/* 3*/   DifferentSign( double ( *F )( double ), double Pt1, double Pt2 )
/* 4*/   {
/* 5*/       return  ( ( *F )( Pt1 ) < 0 ) != ( ( *F )( Pt2 ) < 0 );
/* 6*/   }

/* 7*/   double
/* 8*/   Solve( double ( *F )( double ), double Low, double High )
/* 9*/   {
/*10*/       double Mid = ( Low + High ) / 2.0;
/*11*/       double SmallInterval = ( High - Low ) * Epsilon;

/*12*/       if( ! ( *F )( Low ) )
/*13*/           return Low;
/*14*/       else
/*15*/       if( ! ( *F )( High ) )
/*16*/           return High;
/*17*/       else
/*18*/       if( ! DifferentSign( F, Low, High ) )
/*19*/       {
/*20*/           printf( "Suggested points have same sign!\n" );
/*21*/           return SolveError;
/*22*/       }

/*23*/       while( ( *F )( Mid ) && ( High - Low ) > SmallInterval )
/*24*/       {
/*25*/           if( DifferentSign( F, Low, Mid ) )
/*26*/               High = Mid;
/*27*/           else
/*28*/               Low = Mid;

/*29*/           Mid = ( Low + High ) / 2.0;
/*30*/       }

/*31*/       return Mid;
/*32*/   }