Geometry

Question Analysis  

The main focus is using the co-function identity to relate  to  of its complementary angle for .  

 

Key Concept Explanation  

Co-function identity: . For any angle , the sine of  equals the cosine of its complementary angle .  

 

Step-by-Step Solution  

1. Apply the co-function identity:  

2. Simplify the expression:  

Convert  to twelfths: .  

Thus, .  

 

Option Analysis  

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