1. The problem is not fully specified, but since you mentioned "exercice 2," please provide the full statement of exercise 2 so I can help solve it. 2. To proceed, I need the exact problem details such as the equation, expression, or question asked in exercise 2. 3. Once you provide the problem, I will explain the relevant formulas, rules, and steps to solve it clearly. Please share the full text of exercise 2.