Geometry

Question Analysis  

The main focus is to identify the quadrant where both sine () and cosine () values are negative, using quadrant sign conventions for trigonometric functions.  

 

Key Concept Explanation  

In the unit circle:  

QI: x > 0, y > 0 →  > 0,  > 0.  

QII: x < 0, y > 0 →  < 0,  > 0.  

QIII: x < 0, y < 0 →  < 0,  < 0.  

QIV: x > 0, y < 0 →  > 0,