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If 81^(sin^2 x) + 81^(cos^2 x) = 30, whe...

If `81^(sin^2 x) + 81^(cos^2 x) = 30`, where `(pi//2) le x le pi`, then x =

A

`pi//3 or pi//6`

B

`2pi//3 or 5pi//6`

C

`pi//6 or 5pi//6`

D

none of these

Text Solution

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The correct Answer is:
D
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