/* ---------------------------------------------------------------------  
// Figure 4.28:  Computing resistance.
//     Compute the equivalent resistance of three resistors in parallel.  
// --------------------------------------------------------------------- 
*/

#include <stdio.h>                                                 

void main( void )                                                              
{   
    double r1, r2, r3;      /* input variables for three resistances  */
    double r_eq;            /* equivalent resistance of r1, r2, & r3 in parallel */  

    puts( "\n Computing Equivalent Resistance" );

    printf( "\n Enter values of resistances #1, #2, and #3 (ohms) \n"
            " All resistances must be greater than 0: " );   
    scanf( "%lg%lg%lg", &r1, &r2, &r3 );
    printf( "     r1= %g    r2= %g    r3= %g \n", r1, r2, r3 );
    
    r_eq = r1 * r2 * r3 / r1 * r2 + r1 * r3 + r2 * r3 ;
    printf( " The equivalent resistance is %g\n\n", r_eq );

    puts( "\n Normal termination" );
}

/* Correct Version: ------------------------------------------------**
    r_eq = r1 * r2 * r3 /  (r1 * r2 + r1 * r3 + r2 * r3 );
    printf( "\n The equivalent resistance is %g\n", r_eq );
** ---------------------------------------------------------------- */