$\cos x+\cos y=\frac{4}{5},\cos x-\cos y=\frac{2}{7}$

$\Rightarrow 14\tan \left(\frac{{\displaystyle x-y}}{{\displaystyle 2}}\right)+5\cot \left(\frac{{\displaystyle x+y}}{{\displaystyle 2}}\right)=$

• A

  1

• B

  2

• C

  3

• D

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