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MHT CET202122 Sep 2021Morning ShiftMathematicsProperties of TrianglesActual

In ABC , with usual notations, 2 ab 1 2 ( ~A + B - C )=

Options

  1. Aa^2-b^2-c^2
  2. Ba^2+b^2-c^2
  3. Ca^2+b^2+c^2
  4. Da^2-b^2+c^2

Correct answer

B. a^2+b^2-c^2

Step-by-step solution

aligned & 2 a b 1 2 (A+B-C) & =2 a b 1 2 [( -C)-C]=2 a b ( -2 C 2 ) & =2 a b ( 2 -C )=2 a b C & =2 a b ( a^2+b^2-c^2 2 a b )=a^2+b^2-c^2 aligned

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