C=1/3+1/3^2+1/3^3+….+1/3^100 tính vote 5 sao 07/08/2021 Bởi Quinn C=1/3+1/3^2+1/3^3+….+1/3^100 tính vote 5 sao
`C=1/3+1/3^2+1/3^3+….+1/3^100` `⇒3C=3.(1/3+1/3^2+1/3^3+….+1/3^100)` `⇒3C=1+1/3+1/3^2+1/3^3+….+1/3^99` `⇒3C-C=(1+1/3+1/3^2+1/3^3+….+1/3^99)-(1/3+1/3^2+1/3^3+….+1/3^100)` `⇒2C=1- 1/3^100` `⇒C=(1- 1/3^100)/2` $\color{red}{\text{@Tiểu Bạch}}$ $\color{green}{\text{@Bạch Phượng Cửu}}$ Bình luận
Đáp án: `C = 1/3 + 1/3^2 + 1/3^3 + … + 1/3^{100}` `-> 3C = 1 + 1/3 + 1/3^2 + … + 1/3^{99}` `-> 3C – C = (1 + 1/3 + 1/3^2 + … + 1/3^{99}) – (1/3 + 1/3^2 + 1/3^3 + … + 1/3^{100})` `-> 2C = 1 – 1/3^{100}` `-> C = (1 – 1/3^{100})/2` Bình luận
`C=1/3+1/3^2+1/3^3+….+1/3^100`
`⇒3C=3.(1/3+1/3^2+1/3^3+….+1/3^100)`
`⇒3C=1+1/3+1/3^2+1/3^3+….+1/3^99`
`⇒3C-C=(1+1/3+1/3^2+1/3^3+….+1/3^99)-(1/3+1/3^2+1/3^3+….+1/3^100)`
`⇒2C=1- 1/3^100`
`⇒C=(1- 1/3^100)/2`
$\color{red}{\text{@Tiểu Bạch}}$
$\color{green}{\text{@Bạch Phượng Cửu}}$
Đáp án:
`C = 1/3 + 1/3^2 + 1/3^3 + … + 1/3^{100}`
`-> 3C = 1 + 1/3 + 1/3^2 + … + 1/3^{99}`
`-> 3C – C = (1 + 1/3 + 1/3^2 + … + 1/3^{99}) – (1/3 + 1/3^2 + 1/3^3 + … + 1/3^{100})`
`-> 2C = 1 – 1/3^{100}`
`-> C = (1 – 1/3^{100})/2`