Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

222-9+11+12:2*14+14 = ? ( )

Toán Lớp 7: So sánh A=1/2^1+1/2^2+1/3^3+…+1/2^49+1/2^50 với 1

Toán Lớp 7: So sánh A=1/2^1+1/2^2+1/3^3+…+1/2^49+1/2^50 với 1

Comments ( 2 )

  1. Giải đáp:
     
    Lời giải và giải thích chi tiết:
    M=1-1/2+1/2-1/3+…+1/49-1/50
    M=1+[(-1/2)+1/2)+[(-1/3+1/3)+…+[(-1/49)+1/49]-1/50
    M=1+0+0+…+0-1/50
    M=1+(-1/50)
    M=49/50-

  2. $ A = 1/2 + 1/2^2 + 1/2^3 + … + 1/2^{49} + 1/2^{50} $
    $ 2A = 1 + 1/2 + 1/2^2+…+1/2^{49} $ 
    $ 2A – A = ( 1 + 1/2 + 1/2^2+…+1/2^{49} ) – ( 1/2 + 1/2^2 + 1/2^3 + … + 1/2^{49} + 1/2^{50} ) $ 
    $ A = 1 – 1/2^{50} ⇒ A < 1 $
     

Leave a reply

222-9+11+12:2*14+14 = ? ( )

About Phi Nhung