Calculating various constants required to calculate x3
double f1 = f ( a ) ; double f2 = f ( b ) ; double f3 = f ( c ) ; double d1 = f1 - f3 ; double d2 = f2 - f3 ; double h1 = a - c ; double h2 = b - c ; double a0 = f3 ; double a1 = ( ( ( d2 * Math . Pow ( h1 , 2 ) ) - ( d1 * Math . Pow ( h2 , 2 ) ) ) / ( ( h1 * h2 ) * ( h1 - h2 ) ) ) ; double a2 = ( ( ( d1 * h2 ) - ( d2 * h1 ) ) / ( ( h1 * h2 ) * ( h1 - h2 ) ) ) ; double x = ( ( - 2 * a0 ) / ( a1 + Math . Abs ( Math . Sqrt ( a1 * a1 - 4 * a0 * a2 ) ) ) ) ; double y = ( ( - 2 * a0 ) / ( a1 - Math . Abs ( Math . Sqrt ( a1 * a1 - 4 * a0 * a2 ) ) ) ) ;