6.36.3 The inverse of a series: revert
The revert command finds the beginning of the power series of
a function given the beginning of the series of the function.
-
revert takes one mandatory and one optional argument:
-
series, the beginning of a power series centered at
0 for a function f.
- Optionally x, the name of the variable (by default x).
- revert(series ⟨,x⟩)
returns the beginning of the power series for the
inverse of f; namely the beginning of the power series for
g(f(0)+x) where the function g satisfies g(f(x))=x.
Examples.