A=1/4+1/8+1/6+…..+1/2048 giải giúp mình nha các bạn 24/10/2021 Bởi Elliana A=1/4+1/8+1/6+…..+1/2048 giải giúp mình nha các bạn
`A = 1/4 + 1/8 + 1/16 + …. + 1/2048` `⇒ A = 1/(2^2) + 1/(2^3) + 1/(2^4) + …. + 1/(2^11)` `⇒ 2A = 1/2 + 1/(2^2) + 1/(2^3) + …. + 1/(2^10)` `⇒ 2A – A = 1/2 – 1/(2^11)` `⇒ A = 1/2 – 1/2048` `⇒ A = 1023/2048` Bình luận
1/16 mới đ 1/4 + 1/8+ 1/16+..+ 1/2048 = 1/2^2 + 1/2 ^ 3+…+ 1/2^11 2.A= 1/2+ 1/2^2+….+ 1/2^10 2.A- A= ( 1/2+ 1/2^2+….+ 1/2^10] – ( 1/2^2 + 1/2 ^ 3+…+ 1/2^11] A= 1/2 – 1/2048 = 1024/2048 – 1/2048 = 1023/2048 Học tốt! Bình luận
`A = 1/4 + 1/8 + 1/16 + …. + 1/2048`
`⇒ A = 1/(2^2) + 1/(2^3) + 1/(2^4) + …. + 1/(2^11)`
`⇒ 2A = 1/2 + 1/(2^2) + 1/(2^3) + …. + 1/(2^10)`
`⇒ 2A – A = 1/2 – 1/(2^11)`
`⇒ A = 1/2 – 1/2048`
`⇒ A = 1023/2048`
1/16 mới đ
1/4 + 1/8+ 1/16+..+ 1/2048
= 1/2^2 + 1/2 ^ 3+…+ 1/2^11
2.A= 1/2+ 1/2^2+….+ 1/2^10
2.A- A= ( 1/2+ 1/2^2+….+ 1/2^10] – ( 1/2^2 + 1/2 ^ 3+…+ 1/2^11]
A= 1/2 – 1/2048
= 1024/2048 – 1/2048
= 1023/2048
Học tốt!