某同学在计算3(4+1)(4눀+1)时,把3写成4-1后发现可以连续运用平方差公式计算

2024-12-16 14:31:40
推荐回答(2个)
回答1:

2^2代表2的平方,2^4代表2的4次方……
(1+1/2)(1+1/2^2)(1+1/2^4)(1+1/2^8)+1/2^15
=[(1-1/2)(1+1/2)(1+1/2^2)(1+1/2^4)(1+1/2^8)]/(1-1/2)+1/2^15
=[(1-1/2^2)(1+1/2^2)(1+1/2^4)(1+1/2^8)]/(1-1/2)+1/2^15
=[(1-1/2^4)(1+1/2^4)(1+1/2^8)]/(1-1/2)+1/2^15
=[(1-1/2^8)(1+1/2^8)]/(1-1/2)+1/2^15
=(1-1/2^16)/(1-1/2)+1/2^15
=2-1/2^15+1/2^15
=2

回答2:

原式=(1-1/2)(1+1/2)(1+1/4)(1+1/16)(1+1/256)×2+1/2的15次方
=(1-1/4)(1+1/4)(1+1/16)(1+1/256)×2+1/2的15次方
=(1-1/16)(1+1/16)(1+1/256)×2+1/2的15次方
=(1-1/256)(1+1/256)×2+1/2的15次方
=(1-1/2的16次方)×2+1/2的15次方
=2-1/2的15次方+1/2的15次方
=2
同学你初几?