okay here are some of my answers. one disclaimer - I did not get time to check answers.
q11 a) I) root 2 cis ( - pi /4) ii) -4 / 5 - 2/5 i
b) pi - 6 all over 2 (pi)^2
e) 216 pi units cubed
Q12. b) ii) pi / 18 , 11pi / 18, 13 pi /18
d) iii) 3 pi - 8 all over 12
Q13 a) 2 (root 3) - 3 all...