Answer:
(β2 β β6) / 4
Step-by-step explanation:
Rewrite using special angles.
sin(-11Ο/12)
sin((4β15)Ο/12)
sin(4Ο/12 β 15Ο/12)
sin(Ο/3 β 5Ο/4)
Use angle difference formula:
sin(Ο/3) cos(5Ο/4) β sin(5Ο/4) cos(Ο/3)
Evaluate:
(β3/2) (-β2/2) β (-β2/2) (1/2)
-β6/4 + β2/4
(β2 β β6) / 4