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In a triangle ABC, prove that (b + c)/(a...

In a triangle ABC, prove that `(b + c)/(a) le cosec.(A)/(2)`

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In the triangle ABC,
`(b + c)/(a) = (sin B + sin C)/(sin A)`
`= (2 sin.(B + C)/(2) cos.(B - C)/(2))/(2 sin.(A)/(2). Cos.(A)/(c))`
`= (cos.(B - C)/(2))/(sin.(A)/(2))`
`le (1)/(sin.(A)/(2))`
`rArr (b + c)/(a) le cosec. (A)/(2)`
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