Đặt biểu thức vế trái là A
\(2A=3-\frac{3}{2}+\frac{3}{4}-\frac{3}{8}+...-\frac{3}{512}\)
\(3A=2A+A=3-\frac{3}{1024}\)
\(A=\frac{3A}{3}=1-\frac{1}{1024}< 1\)
chứng minh rằng
a , \(\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{8}-\dfrac{1}{16}+...+\dfrac{1}{512}-\dfrac{1}{1024}\) < \(\dfrac{1}{3}\)
b , \(\dfrac{1}{3}-\dfrac{2}{3^2}+\dfrac{3}{3^3}-\dfrac{4}{3^4}+...+\dfrac{99}{3^{99}}-\dfrac{100}{3^{100}}\) < \(\dfrac{3}{16}\)
Chứng minh:1/2-1/4+1/8-1/16+1/32-1/64+1/128-1/256+1/512-1/1024<1/3
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
1.tính tổng
1+2+3+5+8+.....+55
1+4+16+.....+1024
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
chứng minh 1/2 - 1/4 + 1/8 - 1/16 + 1/32 - 1/64 < 1/3
Chứng minh 1/2 + 1/4 + 1/8 + 1/16+ 1/32 + 1/64 < 1/3
Chứng minh: ( 2x + 3y ) Chia hết cho 17 ki và chỉ khi ( 9x + 5y) chia hết cho 17
Chứng minh rằng
1/2 -1/4+1/8 - 1/16 +1/32-1/64 <1/3
1/3-2/32+ 3/33 - 4/34 + 99/3 -100/3100 <3/16
a) chứng minh rằng
1/2-1/4+1/8-1/16+1/32-1/64<1/3
1/3-2/32+3/33-4/34+...............+99/399-100/3100<3/16
D= 1+2²+2⁴+2⁶+...+2¹⁰⁰
E= 1+3²+3⁴+3⁶+...+3²⁰⁰²
F= 1/2+1/4+1/8+1/16+...+1/1024
G= 1/3+1/3²+1/3³+1/3³+...+1/3¹⁰⁰
Giúp mk vs mấy bn iu ơi,sáng mai mk phải nộp rùi!!
