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Let a,b gt 0 and vecalpha=(veci/a+(4hatj...

Let `a,b gt 0` and `vecalpha=(veci/a+(4hatj)/b+bhatk)` and `vecbeta = bhati+ahatj+1/bhatk`, then the maximum value of `30/(5 + vecalpha.vecbeta)` is

A

1

B

2

C

3

D

8

Text Solution

Verified by Experts

The correct Answer is:
A

`vecalpha.vecbeta = b/a+(4a)/(b)+1ge5`
So, `(10/(5 + vecalpha.vecbeta))_("max")=1`.
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