identity: an equality that remains true regardless of the values of any variables that appear within it, e.g. for multiplication, the identity is one; for addition, the identity is zero Meet Rodney. Seeing profits is music to his ears. | 0:30s Advisory services are provided by TD Ameritrade Investment Management, LLC ("TD Ameritrade Investment Management"), a registered investment advisor. Brokerage services provided by TD Ameritrade, Inc. TD Ameritrade Investment Management provides discretionary advisory services for a fee. Risks applicable to any portfolio are those associated with its underlying securities. For more information, please see the Disclosure Brochure (Form ADV Part 2A).