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Find the least value of sec A+secB+secC ...

Find the least value of `sec A+secB+secC` in an acute angled triangle

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In`/_ABC`
`cosA+cosB+cosC<=3/2`
`secA+secB+secC`
`AM>=HM`
`(secA+secB+secC)/3>=3/(cosA+cosB+cosC)`
`secA+secB+secC>=9/(3/2)`
`secA+secB+secC>=6`.
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