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If in A B C ,A C is double of A B , t...

If in ` A B C ,A C` is double of `A B` , then the value of `cot(A/2)cot((B-C)/2)` is equal to `1/3` (b) `-1/3` (c) `3` (d) `1/2`

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b=2c-(1)
`tan((B-C)/2)=(b-c)/(b+c)cot(A/2)`
`cot(A/2)cot((B-C)/2)=(b+c)/(b-c)=(2c+c)/(2c-c)=3`.
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