\(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right).....\left(1-\frac{1}{999}\right).\left(1-\frac{1}{1000}\right)\)
\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.....\frac{998}{999}.\frac{999}{1000}\)
\(=\frac{1.2.3.....998.999}{2.3.4.....999.1000}\)
\(=\frac{1}{1000}\)
\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{999}\right)\left(1-\frac{1}{1000}\right)\)
\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}....\frac{998}{999}.\frac{999}{1000}\)
\(=\frac{1}{1000}\)
p/s: chúc bạn học tốt
\(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right)........\left(1-\frac{1}{100}\right)\)
\(\Rightarrow\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.....\frac{99}{100}\)
\(\Rightarrow\)BỎ CÁC SỐ: 2;3;4;...;99
\(=\frac{1}{1000}\)
Đáp án là : \(\frac{1}{1000}\)
Tk nha !!
( 1 - 1/2 ) . ( 1 - 1/3 ) . ( 1 - 1/4 ) . ... . ( 1 - 1/999 ) . ( 1 - 1/1000)
= 1/2 . 2/3 . 3/4 . ... . 998/999 . 999/1000
= 1 . 2 . 3 . ... . 998 . 999 / 2 . 3 . 4 . ... . 999 . 1000
= 1/1000