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The least value of 18 sin^(2)theta+2 cos...

The least value of `18 sin^(2)theta+2 cosec^(2)theta-3` is

A

`-15`

B

`-12`

C

0

D

9

Text Solution

Verified by Experts

The correct Answer is:
D
`18 sin^(2)theta+2 cosec^(2)theta-3`
`=(sqrt(18)sin theta - sqrt(2)cosec theta)^(2)+9`
Hence, the least value is 9.
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