" If "z_(r)=cos(2r pi)/(5)+i sin(2r pi)/(5),r=0,1,3,4,.........," then "z_(1)z_(2)z_(3)z_(3)" is equal to - "

If z_(r)=cos.(2rpi)/(5)+isin.(2rpi)/(5) , r=0,1,2,3,4 , then z_(1)z_(2)z_(3)z_(4)z_(5) equals

If quad cos((2r pi)/(5))+i sin((2r pi)/(5)),r=0,1,2,3,4 then z_(1)z_(2)z_(3)z_(4)z_(5) is equal to ,r=0,1,2,3,4

If Z_r=cos((2rpi)/5)+isin((2rpi)/5),r=0,1,2,3,4,... then z_1z_2z_3z_4z_5 is equal to

If z_(k)=cos((k pi)/(10))+i sin((k pi)/(10)), then z_(1)z_(2)z_(3)z_(4) is equal to (A)-1 (B) 2(C)-2 (D) 1

If z_(r)=cos((pi)/(3^(r)))+i sin((pi)/(3^(r))),r=1,2,3 prove that z_(1)z_(2)z_(3)z_(oo)=i

If z_(r)=(cos(pi alpha))/(n^(2))+i(sin(r alpha))/(n^(2)), where r=1,2,3...,n, then lim_(n rarr oo)z_(1)z_(2)z_(3)...z_(n) is equal to

If z^(n) = cos"" (n pi)/(3) + isin"" (n pi)/(3), then z_(1), z_(2) …. Z_(6) is

If z _(r) = cos ((pi)/(2 ^(r))) + i sin ((pi )/( 2 ^(r))), then z _(1) . z _(2). z _(3)... upto oo equals : a)-3 b)-2 c)-1 d)0