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If "cot"(alpha+beta)=0, then "sin"(alph...

If `"cot"(alpha+beta)=0,` then `"sin"(alpha+2beta)` can be (a)`-sinalpha` (b) `sinbeta` (c) `cosalpha` (d) `cosbeta`

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`cot(alpha+beta) = 0`
`=>alpha+beta = pi/2`
Now, `sin(alpha+2beta) = sin(alpha+beta+beta)`
`=sin(pi/2+beta)`
`=cosbeta`
`:. sin(alpha+2beta) = cos beta`
So, option `(d)` is the correct option.
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