* renamed maclaurin_sin.py to maclaurin_series.py and included function for cos approximation
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* attempt to fix pytest error
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
