(a) Whenever any notice is required to be given to any shareholder or director of a corporation under the provisions of this chapter or under the provisions of the articles of incorporation or bylaws of the corporation, a waiver in writing signed by the person or persons entitled to the notice, whether before or after the time stated therein shall be equivalent to the giving of the notice.
(b) The attendance of any shareholder or director at a meeting without protesting, prior to or at the commencement of the meeting, the lack of proper notice shall be deemed to be a waiver by him or her of notice of the meeting.