Question

tính:

A=(1-1/2).(1-1/3).(1-1/4). ....(1-1/2000)

B=(1+1/2).(1+1/3).(1+1/4). ....(1+1/2000)

Answer 1

vào câu hỏi tương tự nhé

Answer 2

A = ( 1 - 1/2 ) . ( 1 - 1/3 ) . ( 1 - 1/4 ) . ... . ( 1 - 1/2000)

A =  ( 2/2 - 1/2 ) . ( 3/3 - 1/3 ) . ( 4/4 - 1/4 ) . ... . ( 2000/2000 - 1/2000 )

A = 1/2 . 2/3 . 3/4 . ... . 1999/2000

A = 1.(2.3. ... . 1999)/ (2.3.4. ... .1999).2000

A = 1/2000

B = ( 1 + 1/2 ).(1 + 1/3 ).( 1+ 1/4 ). ... .(1+1/2000)

B = ( 2/2 + 1/2 ).(3/3+1/3).(4/4+1/4). ... .(1+1/2000)

B = 3/2.4/3.5/4. ... .2001/2000

B = (3.4.5. ... .2000).2001/2.(3.4. ... .2000)

B = 2001/2

B = 1000,5

Answer 3

A=\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{2000}\right)\)

A=\(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{1999}{2000}\)

A=\(\frac{1.2.3.4...1999}{2.3.4.5...2000}\)

A=\(\frac{1}{2000}\)

B=\(\left(1+\frac{1}{2}\right)\left(1+\frac{1}{3}\right)\left(1+\frac{1}{4}\right)...\left(1+\frac{1}{2000}\right)\)

B=\(\frac{3}{2}.\frac{4}{3}.\frac{5}{4}...\frac{2001}{2000}\)

B=\(\frac{3.4.5...2001}{2.3.4...2000}\)

B=\(\frac{2001}{2}\)