Suppose one is given a strictly monotonous polynomial, $$f(x) = \sum_{n=0}^N a_n x^n$$
So that for a given $y$ there exists a single real $x=f^{-1}(y)$. It would be nice* to be able to calculate the inverse value directly using a power series, i.e.:
$$x = \sum_{n=0}^\infty b_n y^n$$
Is there a method of calculating the coefficients for the power series for arbitrary $N$? how about for $N<5$? $$$$ *I'm aware of course that for practical applications iterative methods are the way to go, but this seems like more fun.
This is known as Series Reversion.
The analytical expression for the inverse coefficients can be written out, but it gets quite complex for higher $n$.