Answer:
D
Explanation:
Angle 7π/6 is π/6 below the negative x-axis in the 3rd quadrant. Its cosine will be -(√3)/2.
Angle 11π/6 is π/6 below the positive x-axis in the 4th quadrant. Its cosine will be (√3)/2.
The cosines have the same magnitude, but their signs are opposite each other. Jeremy was not correct.