Excel renamed (and extended) BETADIST and BETAINV to BETA.DIST and BETA.INV.
Currently, Libreoffice does not yet support these renamed functions.
See https://bugs.freedesktop.org/attachment.cgi?id=88108 of meta bug 70798 for test case.
Winfried Donkers committed a patch related to this issue.
It has been pushed to "master":
fdo#71008 add Excel 2010 functions BETA.DEST and BETA.INV
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.