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In a DeltaABC, a(cos^(2)B+cos^(2)C)+cos...

In a `DeltaABC`, `a(cos^(2)B+cos^(2)C)+cosA( c cosC+bcosB)=`

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`a(cos^(2)B+cos^(2)C)+cosA(ccosC+bcosB)`
`=cosB(acosB+bcosA)+cosC(acosC+ccosA)`
`=ccosB+bcosC=a`
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OBJECTIVE RD SHARMA-PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM-Chapter Test
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  12. If the angles A, B, C (in that order) of triangle ABC are in arithmeti...

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  13. If the radius of the incircle of a triangle withits sides 5k, 6k and 5...

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  14. Two sides of a triangle are 2sqrt2 and 2sqrt3cm and the angle opposite...

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