(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)的值
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(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)的值
(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)的值
(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)的值
(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)
=(3-1)(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)/(3-1)
=(3^2-1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)/2
反复用平方差
=(3^128-1)/2
(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)
=(3-1)(3+1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)/(3-1)
=(3^2-1)(3^2+1)(3^4+1)(3^8+1)……(3^64+1)/(3-1)
=(3^4-1)(3^4+1)(3^8+1)……(3^64+1)/(3-1)
=...
==(3^64-1)(3^64+1)/(3-1)
=(3^128-1)/2
(3+1)(3²+1)(3^4+1)(3^8+1)……(3^64+1)
原式=0.5﹙3²-1﹚﹙3²+1﹚﹙3^4+1﹚﹙3^8+1﹚……﹙3^64+1﹚
=0.5﹙3^4-1﹚﹙3^4+1﹚﹙3^8+1﹚……﹙3^64+1﹚
=0.5﹙3^8-1﹚﹙3^8+1﹚……﹙3^64+1﹚
...
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(3+1)(3²+1)(3^4+1)(3^8+1)……(3^64+1)
原式=0.5﹙3²-1﹚﹙3²+1﹚﹙3^4+1﹚﹙3^8+1﹚……﹙3^64+1﹚
=0.5﹙3^4-1﹚﹙3^4+1﹚﹙3^8+1﹚……﹙3^64+1﹚
=0.5﹙3^8-1﹚﹙3^8+1﹚……﹙3^64+1﹚
=0.5﹙3^128-1﹚
=﹙3^128/2﹚-0.5
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