1/2+ 1/3 + 1/(4 )+⋯1/199+1/200 1/199+2/198+3/197+⋯+198/2+199/1

0 bình luận về “1/2+ 1/3 + 1/(4 )+⋯1/199+1/200 1/199+2/198+3/197+⋯+198/2+199/1”

1. =1/199+2/198+3/197+…+197/3+198/2+199/1

               = (1/199+1)+(2/198+1)+(3/197+1)+…+(197/3+1)+(198/2+1)+200/200

               =200/199+200/198+200/197+…+200/3+200/2+200/1+200/200

               =200( 1/200+1/199+1/198+1/197+…+1/3+1/2)

               =200*A

   A/200A=1/200

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