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If 2costheta=x+1/x, then 2cos2theta=?...

If `2costheta=x+1/x`, then `2cos2theta=`?

A

`x^(2)-1/x^(2)`

B

`x^(2)+1/x^(2)`

C

`x-1/x`

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
B
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