Cho A=1-1/2+1/3-1/4+....+1/2001-1/2002
B=1/1002+1/1003+...+1/2002
Tính A/B=?
S = 1 - 1/2 + 1/3 - 1/4 + ... + 1/2001 - 1/2002 P = 1/1002 + 1/1003 + ... + 1/2002 Hỏi S - P = ?
S=\(\left(1+\frac{1}{2}+......+\frac{1}{2002}\right)-2.\left(\frac{1}{2}+\frac{1}{4}+..........+\frac{1}{2002}\right)\)
=\(\left(1+\frac{1}{2}+.........+\frac{1}{2002}\right)-\left(1+\frac{1}{2}+.........+\frac{1}{1001}\right)\)
=\(\frac{1}{1002}+\frac{1}{1003}+...........+\frac{1}{2002}=P\)
\(\Rightarrow S-P=0\)
Bài 1: 65/303 . -48/102 + 65/102
Bài 2: 1- 1/2 + 1/3 - 1/4 + ... + 1/2001 - 1/2002
Bài 3: 1/1002 + 1/1003 + ..... + 1/2002
Thanks
\(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2001}-\frac{1}{2002}\)
\(=\left(1+\frac{1}{3}+...+\frac{1}{2001}\right)-\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2002}\right)\)
\(=1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2002}-2\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2002}\right)\)
\(=1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2002}-1-\frac{1}{2}-...-\frac{1}{1001}\)
\(=\frac{1}{1002}+\frac{1}{1003}+\frac{1}{1004}+...+\frac{1}{2002}\)
Chứng minh rằng: \(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2001}-\frac{1}{2002}=\frac{1}{1002}+\frac{1}{1003}+...+\frac{1}{2002}\)
ta chuyển đề bài vế trái thành:
(1+1/2+1/3+1/4+...+1/2001+1/2002) - 2(1/2+1/4+1/6+...+1/2002)
=(1+1/2+1/3+....+1/2002) - (1+1/2+1/3+1/4+...+1/1001)
=1/1002+1/1003+...+1/2002
=> điều phải chứng minh
S = 1 - 1/2 + 1/3 - 1/4 + ... + 1/2001 - 1/2002
P = 1/1002 + 1/1003 + ... + 1/2002
Hỏi S - P = ?
Các bạn nhớ chỉ cách trình bày luôn nhé!
Cảm ơn nhiều nhé!
Chứng minh rằng:
1 - 1/2 + 1/3 - 1/4 + ... + 1/2001 - 1/2002
= 1/1002 + 1/1003 + ... + 1/2002
Các bạn nhớ chỉ cách trình bày luôn nhé!
Cảm ơn nhiều nhé!
ta chuyển đề bài vế trái thành:
(1+1/2+1/3+1/4+...+1/2001+1/2002) - 2(1/2+1/4+1/6+...+1/2002)
=(1+1/2+1/3+....+1/2002) - (1+1/2+1/3+1/4+...+1/1001)
=1/1002+1/1003+...+1/2002
=> điều phải chứng minh
a, chứng minh rằng : 1-1/2+1/3-1/4+...-1/2000+1/2001-1/2002 = 1/1002+ ...+ 1/2002
giúp mk nha
Xem bài tại link này nhé! Bài làm đúng đã đc OLM chọn.
Câu hỏi của Cristiano Ronaldo - Toán lớp 7 - Học toán với OnlineMath
\(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+....-\frac{1}{2000}+\frac{1}{2001}-\frac{1}{2002}\)
\(=\left(1+\frac{1}{3}+\frac{1}{5}+......+\frac{1}{2001}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{2002}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+....+\frac{1}{2001}+\frac{1}{2002}\right)-2\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+.....+\frac{1}{2002}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+......+\frac{1}{2002}\right)-\left(1+\frac{1}{2}+\frac{1}{3}+......+\frac{1}{1001}\right)\)
\(=\frac{1}{1002}+\frac{1}{1003}+\frac{1}{1004}+.....+\frac{1}{2002}\)
Chúc em học tốt nhé!
giúp mk bài nữa nha
Chứng minh 1-1/2+1/3-1/4+...+1/2002-1/2003 = 1/1002+1/1003+...+1/2003
Đáp án của tớ là:
\(\frac{1}{1002}+\frac{1}{1003}+...+\frac{1}{2003}=\)\(\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2003}\right)-\)\(\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{1001}\right)\)
\(=\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2003}\right)-\)\(\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{2002}\right)-\)\(\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{2002}\right)=\)\(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2003}-\frac{1}{2}-\frac{1}{4}-\frac{1}{6}-...-\frac{1}{2002}\)\(-\frac{1}{2}-\frac{1}{4}-\frac{1}{6}-...-\frac{1}{2002}\)
Vậy:\(1+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{2003}=\frac{1}{1002}+\frac{1}{1003}+...+\frac{1}{2003}\)
xin chòa hôm nay mình sẽ giúp bạn lam bài toán này
ta có
1/1002+1/1003+....+1/2003=(1+1/2+1/3+.....+1/2003)-(1+1/2+1/3+....+1/1001)
1/1002+1/1003+....+1/2003=(1+1/2+1/3+.....+1/2003)-(1/2+1/4+1/6+....+1/2002)-(1/2+1/4+1/6+......+1/2002)
1/1002+1/1003+.....+1/2003=1+1/2+1/3+....+1/2003-1/2+1/4+1/6+....+1/2002-1/2-1/4-1/6-....-1/2002
Vậy1/1002+1/1002+.....+1/2003=1-1/2+1/3-1/4+....-2/2002-1/2003
Sửa: Vậy: \(1-\frac{1}{2}+\frac{1}{3}-...-\frac{1}{2003}=\frac{1}{1002}+\frac{1}{1003}+...+\frac{1}{2003}\)
Cho \(A\) = \(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\)... \(+\frac{1}{2001}-\frac{1}{2002}\) và \(B\) = \(\frac{1}{1002}+\frac{1}{1003}+\)... \(+\frac{1}{2002}\). Tính \(\frac{A}{B}\).
\(A=\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{2001}\right)-\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2002}\right)\)
\(A=\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{2001}\right)+\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2002}\right)-2\times\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2002}\right)\)
\(A=\left(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+...+\frac{1}{1001}+\frac{1}{1002}+...+\frac{1}{2001}+\frac{1}{2002}\right)-\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{1001}\right)\)
\(A=\frac{1}{1002}+\frac{1}{1003}+...\frac{1}{2002}\)= B
=> A/ B = 1
B=1/1002+1/1003+...+1/2002
Tính A/B=?
ai giải được mình tick ;]