C=1/2*3/4*...*199/200.TINH C
tinh r=1/2+1/3+1/4+...+1/200:1/199+2/198+3/197+...+198/2+199/1
tinh A/B biet rang:
A=1/2+1/3+1/4+...+1/200
B =1/199+2/198+3/197+...+198/2+199/1
C=1-2-3-4+5-6-7-8+...+197-198-199-200
C=(1-2-3-4)+(5-6-7-8)+...+(197-198-199-200)
=-8x50
=-400
thuc hien phep tinh
a) 10.72 _ 10.5+10.32
b)15+(_2)_|_7|+8
c) (3^5 .3^3);3^4
d)1+2+3...+199+200
Tinh: S=1-2-3-4-5-...-199-200-201-202.
GIUP MINH VOI, MINH DANG CAN GAP.
S= 2-1-2-3-4-....-201-202
= 2-(1+2+3+4+....+202)
=2- (202:2)( 202+1)
= 2- 101.203
Bài 1 : Tính :
a, D = 1^2 + 3^2 + 5^2 + ..... + 97^2 + 99^2
b. E = 1^2 - 2^2 + 3^2 - 4^2 + ... + 99^2 - 100^2
c,A = 1^2 + 2^2 + .... + 200^2
d, B = 1^2 + 3^2 + 5^2 + ... 199^2
e, C = 2^2 + 4^2 + 6^2 + ... + 200^2
g, H = 1^2 - 2^2 + 3^2 - 4^2 + ... + 199^2 - 200^2
k, M = 1^3 + 2^3 + 3^3 + ..... + 50^3Cho:
A=1/2+1/3+1/4+...+1/200
B = 1/199+2/198+3/197+...+ 197/3+198/2+199/1
Tinh A/B
Bai nay kho nen cac ban giai giup minh nha minh tich dung cho
Ta có: B=1/199+2/198+3/197+...+197/3+198/2+199/1
= (1/199+1)+(2/198+1)+(3/197+1)+...+(197/3+1)+(198/2+1)+200/200
=200/199+200/198+200/197+...+200/3+200/2+200/1+200/200
=200( 1/200+1/199+1/198+1/197+...+1/3+1/2)
=200*A
=> A/B=A/200A=1/200
2^2002^199-2^198-2^197-....-2-1 giải giúp mình với toán lớp 6 đó đề học sinh giỏi nhé
cho C=1/2*3/4*....*199/200
chứng minh Cmũ 2 <1/201
CHO C=1/2*3/4*...*199/200.CHUNG MINH 1/15<C<1/10