In degrees: 3π/4 radians = 135°
Angle of x=135° is in the 2nd Quadrant and has negative cos x values and positive sin x values.
cos 135° = cos ( 90° + 45°)= - sin 45° =

sin 135° = sin ( 90° + 45° ) = cos 45° =

. You can also see the graph in the attachment.
Step-by-step explanation:
câu trả lời là trong hình ảnh trên
1/12 is the answer i think