(a)
Three members of the board shall constitute a quorum for the purpose of transacting any business of the board.(b)
Except as otherwise specifically provided to the contrary in this title, a recorded majority vote of the total authorized membership of the board is required on each action.
Source:
Section 66540.24, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=GOV§ionNum=66540.24..