Representation of a Standard Continuous Function by a Microscope

Autor: Tahir H. Ismail, Hind Y. Saleh
Rok vydání: 2010
Předmět:
Zdroj: Al-Rafidain Journal of Computer Sciences and Mathematics, Vol 7, Iss 2, Pp 115-124 (2010)
ISSN: 2311-7990
DOI: 10.33899/csmj.2010.163901
Popis: The aim of this paper is to provide a representation of a standard continuous function and a standard differentiable function by mean of a microscope. More precisely, under certain conditions, the following results have been obtained. Let 12F"> be a standard continuous function define on 12R"> , and 12°G"> the shadow of it's graph. If there exists a standard point 12X0∈R"> and an interval 12I0"> about 12X0"> such that : 12∀X∈I0,X,FX limited ⟹X≃X0"> . (i) Furthermore If there exist 12X1"> , 12X2"> limited in 12I0"> such that 12FX1"> , 12FX2"> are infinitely large with opposite sign, then 12°G"> contains the vertical line 12∆"> of the equation 12°X=X0"> . (ii) If there exist a standard number 12α"> , 12X∈I0"> and if 12FX"> is limited such that 12°FX≤α"> (resp. 12 °FX≥α"> ). Also if there exist 12X1"> , 12 X2"> limited in 12I0"> such that 12FX1 is infinitely large (resp. 12 FX1>0"> ) and 12FX2≃α"> ,then 12°G"> contains the half line 12∆α"> defined by : 12∆α=X,Y∈R2:°X=X0 , °Y≤α resp.°Y≥α "> Let 12f"> be a standard function defined at a neighborhood at a standard point 12x0"> , then 12f"> is differentiable at 12x0"> if and only if under every microscope of power 12ε"> ,centered at 12x0,fx0"> ,the representation of 12f"> is not a vertical line at 12x0,fx0"> .
Databáze: OpenAIRE