Multiple models for teaching logarithms-with a focus on graphing functions

International audienceThis argumentative paper focuses on graphing logarithmic functions and presents some mathematical knowledge for teaching, employing vom Hofe's construct of basic models (or 'Grundvorstel-lungen') and Sfard's distinction between operational and structural conceptions. On the assumption that difficulties students have with graphing might be a consequence of the standard interpretation of logarithms as inverse exponents, it claims that logarithmic functions should not be introduced structurally, as inverse exponential functions. Instead, several operational models of the logarithmic concept are proposed, and their explanatory power for graphing logarithmic functions is expounded. These models are intended to serve students as a meaningful basis for argumentation