請求化簡分數之值為何:
分子為(1^4+4)(5^4+4)(9^4+4).........(93^4+4)(97^4+4)
分母為(3^4+4)(7^4+4)(11^4+4).........(95^4+4)(99^4+4)?
回答 (2)
Sol
x^4+4=x^4+4x^2+4-4x^2
=(x^2+2)^2-(2x)^2
=(x^2-2x+2)(x^2+2x+2)
=[(x-1)^2+1]*[(x+1)^2+1]
(1^4+4)(5^4+4)(9^4+4).........(93^4+4)(97^4+4)
=[(1-1)^2+1]*[(1+1)^2+1]*[(5-1)^2+1]*[(5+1)^2+1]*[(9-1)^2+1]*[(9+1)^2+1]*…*[(93-1)^2+1]*[(93+1)^2+1]*[(97-1)^2+1]*[(97+1)^2]
=1*5*17*37*65*101*…*8465*8837*9217*9605
(3^4+4)(7^4+4)(11^4+4).........(95^4+4)(99^4+4)?
=[(3-1)^2+1]*[(3+1)^2+1]*[(7-1)^2+1]*[(7+1)^2+1]*[(11-1)^2+1]*[(11+1)^2+1]*…*[(95-1)^2+1]*[(95+1)^2+1]*[(99-1)^2+1]*[(99+1)^2]
=5*17*37*65*101*145*…*8837*9217*9605*10001
A=1/10001
收錄日期: 2021-04-30 22:41:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20180704063923AAkNFk7
檢視 Wayback Machine 備份