(a) The act of a majority of the directors present at a meeting at which a quorum is present at the time of the act is the act of the board of directors of a corporation, unless the act of a greater number is required by the certificate of formation or bylaws of the corporation or by this code.
(b) Unless otherwise provided by the certificate of formation or bylaws, a written consent stating the action taken and signed by all members of the board of directors is also an act of the board of directors.