1 )Tính căn bậc 9 của 2 số phức sau rồi viết dưới dạng góc radian: $w_{1}=i$, $w_{2}=-i$A)$z_{1}$= $-sin(\frac{\pi}{9})+cos(\frac{\pi}{9})i$ & $z_{2}$=$sin(\frac{\pi}{9})-cos(\frac{\pi}{9})i$
B)$z_{1}$= $-sin(\frac{-17\pi}{12})+cos(\frac{-17\pi}{12})i$ & $z_{2}$= $sin(\frac{-17\pi}{12})-cos(\frac{-17\pi}{12})i$
C))$z_{1}$= $-sin(\frac{\pi}{9})-cos(\frac{\pi}{9})i$ & $z_{2}$=$sin(\frac{\pi}{9})+cos(\frac{\pi}{9})i$