Elliptic Curves Over The Rational Numbers
A curve E defined over the field of rational numbers is also defined over the field of real numbers, therefore the law of addition (of points with real coordinates) by the tangent and secant method can be applied to E. The explicit formulae show that the sum of two points P and Q with rational coordinates has again rational coordinates, since the line joining P and Q has rational coefficients. This way, one shows that the set of rational points of E forms a subgroup of the group of real points of E. As this group, it is an abelian group, that is, P + Q = Q + P.
Read more about this topic: Elliptic Curve
Famous quotes containing the words curves, rational and/or numbers:
“At the end of every diet, the path curves back toward the trough.”
—Mason Cooley (b. 1927)
“Since the Greeks, Western man has believed that Being, all Being, is intelligible, that there is a reason for everything ... and that the cosmos is, finally, intelligible. The Oriental, on the other hand, has accepted his existence within a universe that would appear to be meaningless, to the rational Western mind, and has lived with this meaninglessness. Hence the artistic form that seems natural to the Oriental is one that is just as formless or formal, as irrational, as life itself.”
—William Barrett (b. 1913)
“All experience teaches that, whenever there is a great national establishment, employing large numbers of officials, the public must be reconciled to support many incompetent men; for such is the favoritism and nepotism always prevailing in the purlieus of these establishments, that some incompetent persons are always admitted, to the exclusion of many of the worthy.”
—Herman Melville (1819–1891)