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Grade 11Trigonometry

Proved that acosA+bcosB+ccosC=2asinBsinC please help sir

Profile image of Aditya
9 Years agoGrade 11
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1 Answer

Profile image of Vikas TU
9 Years ago
Use properties of triangles.
let area of triangle be Ar.
Then bcsinA= casinB = absinC = 2Ar
thus write all sin terms in terms of Ar.
and also use
a/sinA = b/sinB = c/sinC = k.