Các câu hỏi tương tự
cho A =1/2*3/4*5/6*...*99/100
B=2/3*4/5*6/7*...*100/101
C=1/2*2/3*4/5*...*98/99
a) so sanh A, B, C
b) Chung minh: A*C< A^2< 1/10
c) Chung minh: 1/15< A< 1/10
Lam giup minh di ai lam duoc minh tich dung cho
cho b= 1/2-1/3+1/4-1/5+.....+1/98-1/99 chung minh 0,2<B<0.4
chung minh rang : 1 / 2 ^ 2 + 1 / 3 ^ 2 + 1 / 4 ^ 2 + . . . + 1 / 100 ^ 2 < 99 / 100
Cho A=1/42 + 1/52 + 1/62 + .... + 1/992 + 1/1002.
Chung minh: 1/5 < A < 1/3.
1.Chưng minh rằng (1+/1/3+1/5+....+1/99)-(1/2+1/4+1/6+...+1/100)=1/51+1/52+...+1/100
2.Áp dụng phan 1 để chung minh 1-1/2+1/3-1/4+.....-1/200=1/101+1/102+.......+1/200
Cho A=1/42 + 1/52 + 1/62 + .... + 1/992 + 1/1002.
Chung minh: 1/5 < A < 1/3.
chung minh rang 1/3-2/3^2+3/3^3-4/3^4+....+99/3^99-100/3^100<3/16
a)chung minh A= 2^1+2^2+2^3+2^4+...2^2010chia het cho 3
b)chung minh B= 3^1+3^2+3^3+3^4+...3^2010chia het cho 4
c)chung minh C= 5^1+5^2+5^3+5^4+...5^2010chia het cho 6
d)chung minh D= 7^1+7^2+7^3+7^4+...7^2010chia het cho 8
Cho minh hoi vai bai:
Bài 1: chứng minh
A=1/100+1/101+...+1/200>1/2
B=1/21+1/22+1/23+... Chung minh 5/6<B<4/3
C=1/2^2+1/3^2+...+1/99^2+1/100^2 <3/4
Bai2: tìm x, y
A) x/3-1/y=1/3
B)1/x+y/2=-1/3
C)x/5-2/y=2/15