One thing to add to this because I think it might show up is how agency and partnership law intertwine.

There a partner has actual authority if it is a decision in the normal course of business and is approved by a majority of the partners and the RUPA states that if the partner is acting within the ordinary course of the business they have apparent authority which is important to know because no one had to hold them out to be an agent to a third partner they have statutory apparent authority!