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If 5(tan^2x - cos^2x)=2cos 2x + 9, then ...

If `5(tan^2x - cos^2x)=2cos 2x + 9`, then the value of `cos4x` is

A

`-(7)/(9)`

B

`-(3)/(5)`

C

`(1)/(3)`

D

`(2)/(9)`

Text Solution

Verified by Experts

The correct Answer is:
A
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