z1*z2=5 exp(pi/4 I) *6 exp (pi/9 I)=30 exp (13pi/36 I)
z1/z2= 5/6 exp (5pi/36 I)
z1^10= 5^10 exp(10pi/4 I)
5 exp(pi/4 I)= 5 (cos pi/4 +I sin pi/4)=5 sqrt(2)/2 (1+ I)
z1*z2=5 exp(pi/4 I) *6 exp (pi/9 I)=30 exp (13pi/36 I)
z1/z2= 5/6 exp (5pi/36 I)
z1^10= 5^10 exp(10pi/4 I)
5 exp(pi/4 I)= 5 (cos pi/4 +I sin pi/4)=5 sqrt(2)/2 (1+ I)