Show that 9 pi /8 -9/4 sin-1 1/3 = 9/4 sin-1 2 root 2/3 Share with your friends Share 2 Manbar Singh answered this 94 sin-1223 + 94sin-113 =94sin-1223 + sin-113=94sin-1223×1-19+131-89=94sin-189+19=94sin-11=94×π2=9π8So, 9π8 - 94sin-113 =94 sin-1223 3 View Full Answer Abhishek Shukla answered this 9/4(sin-1-sin-1(1/3))= 9/4(sin-1root(9-1)/3)= 9/4sin-1(2root(2)/3) 3