Arg of sin(16∏/15)+i(1+ cos(16∏/15)

hi

here u can write 1+ cos(16∏/15) = 2cos² (8∏/15) ......[1+cosx = 2cos^2(x/2).................]

also write sin(16∏/15) = 2sin(8∏/15)cos(8∏/15)

now d expression becomes

2cos(8∏/15)[sin(8∏/15) +i cos(8∏/15) ]

so ur arg wud be simply 8∏/15