Final answer:
Informal executive powers in conducting foreign policy that provide the president with an advantage over Congressional authority include making informal executive agreements with foreign governments and using executive orders.
Step-by-step explanation:
Informal executive powers in conducting foreign policy that provide the president with an advantage over Congressional authority include making informal executive agreements with foreign governments and using executive orders. Informal executive agreements allow the president to bypass the requirement for Senate approval of formal treaties. Examples of executive agreements include the Vietnam War and NAFTA. Additionally, executive orders allow the president to make rules without the need for Congress to pass legislation. These informal powers give the president more flexibility and speed in making foreign policy decisions compared to the slower legislative process of Congress.