MATHEMATICS · Single correct · CBSE · Mathematics · Complex Numbers and Quadratic Equations · Complex Numbers and Quadratic Equations
Problem
For positive integers n1,n2 , the value of expression (1+i)n1+(1+i3)n1+(1+i5)n2+(1+i7)n2 , where i=−1 is a real number, if and only if
(1) (B) n1=n2−1
(2) (A) n1=n2+1
(3) (D) n1>0,n2>0
(4) (C) n1=n2