InverseSeries

InverseSeries[s] gives a series for the inverse of the function represented by series s.

InverseSeries[s, x] uses variable x in the result.

Examples

Inverse series:

s = Series[Sin[x], {x, 0, 5}];
InverseSeries[s]

Verify:

Normal[InverseSeries[s]] /. x -> Sin[y]

Please visit the official Wolfram Language Reference for more details.