3.6.5 Converting Power Series to Normal Expressions
Converting power series to normal expressions.
As discussed above, power series in Mathematica are represented in a special internal form, which keeps track of such attributes as their expansion order.
For some purposes, you may want to convert power series to normal expressions. From a mathematical point of view, this corresponds to truncating the power series, and assuming that all higher-order terms are zero.
This generates a power series, with four terms.
Squaring the power series gives you another power series, with the appropriate number of terms.
Normal truncates the power series, giving a normal expression.
You can now apply standard algebraic operations.
Extracting coefficients of terms in power series.
This gives the coefficient of in the original power series.