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If in a triangleABC, BC=(e)/(|e|)-(f)/(|...

If in a `triangleABC, BC=(e)/(|e|)-(f)/(|f|) and AC=(2e)/(|e|): |e|ne|f|,` then the value of `cos2A+cos2B+cos2C` must be

A

(a)`-1`

B

(b)`0`

C

(c)`2`

D

(d)`(-3)/(2)`

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A
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