Question

100分数学题初中5分钟解决+50分

Answer 1

原式=2*(1-1/2)(1+1/2)(1+1/2^2)*(1+1/2^4)...(1+1/2^128)+2^(-255)

=2(1-1/2^2)(1+1/2^2)*(1+1/2^4).(1+1/2^128)+2^(-255)

=2(1-1/2^4)*(1+1/2^4)...(1+1/2^128)+1/2^255

=...

=2(1-1/2^128)(1+1/2^128)+1/2^255

=2(1-1/2^256)+1/2^255

=2-1/2^255+1/2^255

=2