Sir please solve this

Asked by spuneet23 | 12th Sep, 2010, 08:08: PM

Expert Answer:

acosA+bcosB+ ccos C
=(k/2)[ 2sin AcosA+2sinBcosB+2sinC cosC]
=(k/2)[ sin2A+sin2B+sin2C]
=(k/2)[2sinCcos(A-B)+sin2C]
=k sinC[ cos(A-B)-cos(A+B)]
=ksin C [2sinAsinB]
=2(ksinA)sinBsinC
=2asinBsinC
=
=r/R

Answered by  | 13th Sep, 2010, 11:18: AM

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