ከ«ኦይለር ቁጥር» ለውጦች መካከል ያለው ልዩነት

[[Imageስዕል:Exp derivative at 0.svg|right|frame|''e'' is the unique number ''a'', such that the value of the derivative (the slope of the tangent line) of the exponential function ''f'' (''x'') = ''a^x'' (blue curve) at the point ''x'' = 0 is equal to 1. For comparison, functions 2^''x'' (dotted curve) and 4^''x'' (dashed curve) are shown; they are not tangent to the line of slope 1 (red).]]