Algebra-2

Question Analysis
This question calculates the period of a cosine function with a negative, fractional B-value.The main focus is on using the absolute value of B (to ignore reflection) and simplifying division by a negative fraction.

Key Concept Explanation
A negative B only reflects the cosine graph horizontally (no effect on period length). Thus, we first take to get a positive value, then calculate the period by dividing by (using reciprocals for fractions).

Step-by-step Solution
1. Identify and find .
2. Apply the formula: .
3. Multiply by the reciprocal: