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:
“For a hundred and fifty years, in the pasture of dead horses,
roots of pine trees pushed through the pale curves of your ribs,
yellow blossoms flourished above you in autumn, and in winter
frost heaved your bones in the ground—old toilers, soil makers:
O Roger, Mackerel, Riley, Ned, Nellie, Chester, Lady Ghost.”
—Donald Hall (b. 1928)
“I have always been a friend to hero-worship; it is the only rational one, and has always been in use amongst civilized people—the worship of spirits is synonymous with barbarism—it is mere fetish.... There is something philosophic in the worship of the heroes of the human race.”
—George Borrow (1803–1881)
“The only phenomenon with which writing has always been concomitant is the creation of cities and empires, that is the integration of large numbers of individuals into a political system, and their grading into castes or classes.... It seems to have favored the exploitation of human beings rather than their enlightenment.”
—Claude Lévi-Strauss (b. 1908)