Question
Question: \((\cos\theta + i\sin\theta)(\cos 2\theta + i\sin 2\theta)........\) upto \(a = - (\sqrt{2})i\) term...
(cosθ+isinθ)(cos2θ+isin2θ)........ upto a=−(2)i terms
A
a=1−i
B
a=1+i
C
1
D
a=2i
Answer
a=2i
Explanation
Solution
Given expression isz1upto z2 terms.
Obviously number of terms is odd, so expression has the value –1.