(1-2/2.3)(1-2/3.4)(1-2/4.5)...(1-2/99.100)
S = ( 1-2/2.3).(1-2/3.4).(1-2/4.5).....(1-2/2015.2016)
E=((2/2.3-1).(2/3.4-1).(2/4.5-1).....(2/2019.2020-1)
Tính: C=1 + 1/2 x 2.3/2 +1/3 x 3.4/2 +1/4 x 4.5/2 +.............+1/20 x 20.21/2
Tính: (1-2/2.3).(1-2/3.4).(1-2/4.5)...(1-2/98.99)
\(\left(1-\frac{2}{2.3}\right)\left(1-\frac{2}{3.4}\right)\left(1-\frac{2}{4.5}\right)......\left(1-\frac{2}{99.100}\right)\)
\(B=\left(1-\frac{2}{2.3}\right).\left(1-\frac{2}{3.4}\right).\left(1-\frac{2}{4.5}\right)....\left(1-\frac{2}{99.100}\right)\)
tính
\(\left(1-\frac{2}{2.3}\right).\left(1-\frac{2}{3.4}\right).\left(1-\frac{2}{4.5}\right)...\left(1-\frac{2}{99.100}\right)\)
TÍNH HỢP LÝ
B=\(\left(\frac{2}{2.3}-1\right)\left(\frac{2}{3.4}-1\right)\left(\frac{2}{4.5}-1\right)...\left(\frac{2}{2008.2009}-1\right)\)