# $1+i+i^{2}+i^{3} + i^{4}+i^{5}+i^{6}---+i^{2n}\;$ is

$(a)\;Positive\qquad(b)\;Negative\qquad(c)\;0\qquad(d)\;Can\;not\;be\;evaluated$

Answer : Can not be evaluated
Explanation :
$1+i+i^{2}+i^{3} + i^{4}+i^{5}+i^{6}---+i^{2n}\; =1-1+1-1--+(-1)^{n}$
Which Can not be evaluated unless n is known .