The circle with a radius of one unit is partitioned into twelve equal arcs, where each arc corresponds to specific t-values. Determine the value of the trigonometric function at the given real number t using the (x,y) coordinates in the diagram or specify that the expression is undefined.

sec(7π/6)

• A. -(2√3)/3
• B. (2√3)/3
• C. -(√3)/2
• D. (√3)/2

Answer: (A)