Final answer:
The complementary angle identity sin(π/n - x) equals cos(x) when n = 2. This follows from the co-function identity stating that sine and cosine are complementary functions.
Step-by-step explanation:
The complementary angle identity for the sine function is given by sin(π/n - x). This identity can be understood through the co-function identity, which states that sine and cosine are complementary. This means for any acute angle, the sine of the angle is equal to the cosine of its complement. The complement of x is (π/2) - x, so sin(π/n - x) would be equal to cos(x) if n = 2. Thus, the correct answer to the given question is (a) cos(x).