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Which term of the sequence 8-6i ,7-4i ,6...

Which term of the sequence `8-6i ,7-4i ,6-2i , ` is purely real ?

A

4th

B

5th

C

6th

D

7th

Text Solution

Verified by Experts

The correct Answer is:
A
`a=8-6i`
`d=7-4i-8+6i`
`=-1+2i`
`a_n=a+(n-1)d`
`a+ib=8-6i+(n-1)(-1+2i)`
`a+ib=8-6i+(-1)(n-1)+(n-1)2i`
`-6+2(n-1)=0`
`2(n-1)=6`
...
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