math Definition Exponential Function An exponential function is a function where the function’s parameters are exponents. Examples: f(x)=ex f(x)=ax with a∈R+ Bijectivity The exponential function is bijective from R to R+. Continuity Continuity of Exponential Functions Exponential functions of form f(x)=ex,f(x)=ax with e being the Euler’s number and a>0 are continuous.