1.Chứng minh rằng a)1/2-1/4+1/8-1/16+1/32-1/64<1/3 b)1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16

Chưng tỏ

a, S= 1/2^2+1/3^2+...+1/9^2 

Chứng tỏ 2/5<S<8/9

b, 1/2-1/4+1/8-1/16+1/32-1/64<1/3

c, 1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16

CMR:

a)1/2-1/4+1/8-1/16+1/32-1/64<1/3

b)1/3 - 2/3^2 + 3/3^3 - 4/3^4 +...+ 99/3^99 -100/3^100 < 3/16

cmr

a) 1/2 -1/4+1/8-1/16+1/32-1/64 <1/3

b) 1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16

Chứng minh rằng:

a) 1/2-1/4+1/8-1/16+1/32-1/64<1/3

b) 1/3-2/3^2+3/3^3-3/3^4+...+99/3^99-100/3^100<3/16

Tính nhanh:

a) (2^2+4^2+6^2+......+100^2)-(1^2+3^2+5^2+........+99^2)

b) 8(3^2+1)(3^4+1)(3^8+1)(3^16+1)-3^32

Giải giúp mình đi . ghi ra tùng bước mình cảm ơn nhiều , cho mọi người 1tick.

Chứng tỏ 

a, 1/2-1/4+1/8-1/16+1/32-1/64<1/3

b, 1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16

c, 1/2.3/4.5/6...9999/10000<1/100

bai 1) tim x, y

x.y-x+2y=3

bai2 ) cmr

a)1/2-1/4+1/8-1/16+1/32-1/64<1/3

b) 1/3-2/3^2+3/3^3-4/3^4+....+99/3^99-100/3^100<3/16

c)1cho tổng gồm 2014 số hạng : s=1/4+2/4^2+3/4^3+.....2014/4^2014

a) 1/2 - 1/4 + 1/8 - 1/16 + 1/32 - 1/64 < 1/3

b) 1/3 - 2/3² + 3/3³ - 4/3⁴ +...+ 99/3⁹⁹ - 100/3¹⁰⁰ < 3/16