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In A B C , prove that (a-b)^2cos^2C/2+(...

In ` A B C ,` prove that `(a-b)^2cos^2C/2+(a+b)^2sin^2C/2=c^2dot`

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`L.H.S. = (a^(2) + b^(2) - 2ab) cos^(2).(C)/(2) + (a^(2) + b^(2) + 2 ab) sin^(2). (C)/(2)` `= a^(2) + b^(2) + 2ab (sin^(2).(C)/(2) - cos^(2).(C)/(2))`
`= a^(2) + b^(2) - 2ab cos C`
`= c^(2)` (Using consine Rule)
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CENGAGE PUBLICATION-PROPERTIES AND SOLUTIONS OF TRIANGLE-Illustration
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  2. The base of a triangle is divided into three equal parts. If t1, t2,t3...

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  3. In A B C , prove that (a-b)^2cos^2C/2+(a+b)^2sin^2C/2=c^2dot

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  4. In A B C ,= if (a+b+c)(a-b+c)=3a c , then find /Bdot

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