It will not utilize exactly Robinson's formulation. The purpose of this material is to explain, illustrate and justify the non-standard analysis formulation of infinitesimals.
Robinson called his formulation non-standard analysis. There were however a large number of recalcitrants who kept the comfortable nonsense of infinitesimals alive.Īnd then in 1960 Abraham Robinson founda way to provide a rigorous foundations for infinitesimals and thus infinitesimals were acceptable, although not exactly welcome, again in mathematical discourse. In the latter nineteenth century the German mathematician Karl Weierstrauss introduced the epsilon-delta process which provided a rigorous basis for the calculus and mathematics instructors thereafter discouraged students from using the infinitesimal concept. Nevertheless researchers found the infinitesimal concept, useful even essential, for developing the differential calculus. I therefore cast them out…Ĭlearly the concept of an infinitesimal was pretty fuzzy. Those terms for the ratio that which had an infinitesimal as a factor were equatedĮrms which have as a factor will be equivalent to nothing in respect to the others. Newton's analysis involved taking ratios of infinitesimals. In effect he was saying that the although infinitesimals are not zero the product of infinitesimals is zero. Who introduced the d notation for differentials, said in deriving d(xy)=xdy+ydx that this follows fromĭ(xy) = (x+dx)(y+dy) − xy = xdy + ydx + dxdyĪnd the omission of the quantity dxdy, which is infinitely small in comparison with the rest, for it is supposed that dx and dy are infinitely small. Of an infinitesimal, which they referred to as an infinitely small number, whatever that was supposed to mean. When Isaac Newton and Gottfried Wilhelm Leibniz first formulated differential calculus they effectively made use of the concept