A New Rational Approach to the Square Root of 5

In this paper, authors construct a new type of sequence which is named an extra-super increasing sequence, and give the definitions of the minimal super increasing sequence {a[0], ..., a[l]} and minimal extra-super increasing sequence {z[0], ...,[z]l}. Discover that there always exists a fit n which makes (z[n] / z[n-1] - a[n] / a[n-1])= PHI, where PHI is the golden ratio conjugate with a finite precision able to be expressed by computers. Further, derive the formula radic(5) = 2(z[n] / z[n-1] - a[n] / a[n-1]) + 1, where n corresponds to the demanded precision. Experiments demonstrate that the approach to radic(5) through a ratio difference is more smooth and expeditious than through a Taylor power series, and convince the authors that lim{n to infinity} (z[n] / z[n-1] - a[n] / a[n-1]) = PHI holds.