Find the value of cos-1 (cos 2pi / 3 ) + sin-1 ( sin 2pi/3 ) Share with your friends Share 10 Prasanta answered this cos-1cos2π3+sin-1sin2π3=cos-1-12+sin-132 =π-cos-112+sin-132=π-cos-1cosπ3+sin-1sin2π3 =π-π3+2π3 =4π3 -49 View Full Answer Ruby Tanveer answered this Cos inv. ( cos2pi/3) + sin inv. (sin 2pi/3) = cos inv. (cos 2pi/3) + sin inv. (sin pi - pi/3) =. 2pi/3 + sin inv. ( sin pi/3) = 2pi/3 + pi/3 = pi 30 Trishna answered this Thank you 13