1. The problem is to find the principal solution(s) when given that \( \text{CONCETO} = -6 \).\n\n2. The term "principal solution" typically refers to the main or primary solution within a specified domain, often used in trigonometry or equations involving periodic functions.\n\n3. However, the problem does not provide an explicit equation or function related to the value -6, so let's clarify the likely intent.\n\n4. If "CONCETO" is intended as a variable or function name equal to -6, then the principal solution depends on the equation or problem context, which is missing here.\n\n5. Without more information, we cannot determine a principal solution. Please provide the full equation or problem statement to proceed.\n