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If x(n)=cos(pi/2^(n))+isin(pi/2^(n)), n ...

If `x_(n)=cos(pi/2^(n))+isin(pi/2^(n)), n in N` then `x_(1),x_(2),x_(3)………………..x_(infty)`. Is equal to

A

1

B

`-1`

C

0

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
B
We have,
`x_(n)=e^(i2pi//n),n=1,2,3,………….`
`therefore x_(1)x_(2)x_(3)……..x_(infty)=e^(ipi(1/2+1/2^(2)+1/2^(3)+…..infty)=e^(ipi)=-1`
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  19. If 2z1-3z2 + z3=0, then z1, z2 and z3 are represented by

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