Exponential function Maclaurin

In general, the donor and receiver concentrations are exponential functions of time. It is only within the early time period when no more than 10-15% of CD(0) has been transported that the kinetics are essentially linear hence, the tmncated Maclaurin s expansion of Eqs. (5) and (7) leads to the linear relationships... 

Equation (2.13) is not yet in a form that is fundamentally different from the Cartesian form expressed in equation (2.5). However, we can obtain an alternative, more compact, and far more powerful way of writing the polar form of a complex number by re-visiting the Maclaurin series for the sind, cos6 and exponential functions. The Maclaurin series for cosine and sine are ... 

In fact, the proportional error model and exponential error model are equal for small values of a. To see this, the function exp(x) if first written as a MacLaurin series... 

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