tinh nhanh
(1-1/2010).(1-2/2010).(1-3/2010).......(1-2011/2010)
tinh nhanh B=1/1+2009/2011+2009/2010 + 1/1+2010/2009+2010/2011 + 1/1+2011/2009+2011/2010
tinh tong :
1/1:2+1/2:3+1/3:4+...+1/2009:2010+1/2010:2011
a) 2010/1+2009/2+2008/3+ ... +1/2010+2010 : 1+1/2+1/3+ ... +1/2010=
b) 1/2011+1/2010+1/2009+ ... +1/3+1/2 : 2010/1+2009/2+2008/3+ ... +1/2010=
A=( 1 -1/2010) (1 - 2/2010) ( 1- 3/2010) ... ( 1- 2011/2010) = ?
Tính tích
A=(1-1/2010).(1-2/2010).(1-3/2010). ... .(1-2011/2010)
A= (1-1/2010) x (1- 2/2010) x (1- 3/2010) x.... x( 1- 2011/2010) =?
Vì ta có 1 - 1/2010 = 0/2010 = 0 nên suy ra biểu thức A = 0
A=\(\left(1-\frac{1}{2010}\right).\left(1-\frac{2}{2010}\right)...\left(1-\frac{2010}{2010}\right)\left(1-\frac{2011}{2010}\right)\)
A=\(\frac{2009}{2010}.\frac{2008}{2010}...0.\frac{-1}{2010}\)
A=0
Tính tích ; A= (1-1/2010).(1-2/2010).(1-3/2010)...(1-2011/2010)
Ta có:\(1-\frac{2010}{2010}=1-1=0\)
Tích A= (1-1/2010).(1-2/2010).(1-3/2010)....(1-2011/2010) chứa thừa số \(1-\frac{2010}{2010}=0\)
Vậy tích A=(1-1/2010).(1-2/2010).(1-3/2010)....(1-2011/2010)=0(Vì có chứa thừa số 0)
Ta có \(1-\frac{2010}{2010}=1-1=0\)
Mà \(A=\left(1-\frac{1}{2010}\right).\left(1-\frac{2}{2010}\right).\left(1-\frac{3}{2010}\right)...\left(1-\frac{2010}{2010}\right).\left(1-\frac{2011}{2010}\right)\)
Nên \(A=...0\)\(=0\)
Tính
A=(1-1/2010).(1-2/2010).(1-3/2010). ... .(1-2011/2010)
Tính
A=(1-1/2010).(1-2/2010).(1-3/2010). ... .(1-2011/2010)
\(A=\dfrac{2009}{2010}\cdot\dfrac{2008}{2010}\cdot...\cdot\dfrac{2}{2010}\cdot\dfrac{1}{2010}\cdot\dfrac{0}{2010}\cdot\dfrac{-1}{2010}\)
=0