To prove a system is in equilibrium, one can demonstrate that the sum of forces in all directions (ΣFx = 0 and ΣFy = 0) is zero, indicating mechanical equilibrium. Additionally, one can analyze the system's energy, calculating it as a function of position, differentiating, and setting the result to zero to find equilibrium positions. Different types of equilibrium exist, including thermal equilibrium, but all share the characteristic of an energy minimum or plateau. Understanding these principles is essential for confirming a system's equilibrium state. The discussion emphasizes the importance of both force balance and energy considerations in proving equilibrium.