1+2+1+2+1+2+1+2+1+2+1+2+1+2 =( )*( ) =()
1+2+1+2+1+2+1+2+1+2+1+2+1+2 =( )*( ) =()
1*1/2=?
1+1×2=?
1、-|-1/2|=?
√[1+1/(1^2)+1/(2^2)] = 1+1/1-1/2=1+1/2
已知S1=1+1/1^2+1/2^2
(1+1/2)(1+1/2^2)(1+1/2^4)(1+1/2^8)+1/2^15=?
1 1 1 1------ + ------ + ------ + .+ -------------- =1×2 2×3
1+2+2+2+2=积分
x_n = (n^2)^(-1/2) + (n^2+1)^(-1/2) + (n^2+2)^(-1/2) + ...+
1 2 1 2 () () ()()
(1)1/2=1/(1*2)=1/1-1/2