已知a²-3a+1=0,求a²+1/a^21(a的平方加a的21次方分之一)的值注:其实原题是 :已知a²-3a+1=0,求a²+1/a(a的平方+a分之一)和a²+1/a^21(a的平方加a的21次方分之一)的值.我第一题会
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![已知a²-3a+1=0,求a²+1/a^21(a的平方加a的21次方分之一)的值注:其实原题是 :已知a²-3a+1=0,求a²+1/a(a的平方+a分之一)和a²+1/a^21(a的平方加a的21次方分之一)的值.我第一题会](/uploads/image/z/13703630-14-0.jpg?t=%E5%B7%B2%E7%9F%A5a%26%23178%3B-3a%2B1%3D0%2C%E6%B1%82a%26%23178%3B%2B1%2Fa%5E21%EF%BC%88a%E7%9A%84%E5%B9%B3%E6%96%B9%E5%8A%A0a%E7%9A%8421%E6%AC%A1%E6%96%B9%E5%88%86%E4%B9%8B%E4%B8%80%EF%BC%89%E7%9A%84%E5%80%BC%E6%B3%A8%EF%BC%9A%E5%85%B6%E5%AE%9E%E5%8E%9F%E9%A2%98%E6%98%AF+%EF%BC%9A%E5%B7%B2%E7%9F%A5a%26%23178%3B-3a%2B1%3D0%2C%E6%B1%82a%26%23178%3B%2B1%2Fa%EF%BC%88a%E7%9A%84%E5%B9%B3%E6%96%B9%2Ba%E5%88%86%E4%B9%8B%E4%B8%80%EF%BC%89%E5%92%8Ca%26%23178%3B%2B1%2Fa%5E21%EF%BC%88a%E7%9A%84%E5%B9%B3%E6%96%B9%E5%8A%A0a%E7%9A%8421%E6%AC%A1%E6%96%B9%E5%88%86%E4%B9%8B%E4%B8%80%EF%BC%89%E7%9A%84%E5%80%BC.%E6%88%91%E7%AC%AC%E4%B8%80%E9%A2%98%E4%BC%9A)
已知a²-3a+1=0,求a²+1/a^21(a的平方加a的21次方分之一)的值注:其实原题是 :已知a²-3a+1=0,求a²+1/a(a的平方+a分之一)和a²+1/a^21(a的平方加a的21次方分之一)的值.我第一题会
已知a²-3a+1=0,求a²+1/a^21(a的平方加a的21次方分之一)的值
注:其实原题是 :已知a²-3a+1=0,求a²+1/a(a的平方+a分之一)和a²+1/a^21(a的平方加a的21次方分之一)的值.
我第一题会做的,求a²+1/a^21(a的平方加a的21次方分之一)的值.
已知a²-3a+1=0,求a²+1/a^21(a的平方加a的21次方分之一)的值注:其实原题是 :已知a²-3a+1=0,求a²+1/a(a的平方+a分之一)和a²+1/a^21(a的平方加a的21次方分之一)的值.我第一题会
a²-3a+1=0 a=(3±√5)/2
(1) a=(3+√5)/2 1/a=2/(3+√5)=(3-√5)/2
a²+1/a^21=[(3+√5)/2]^2+[(3-√5)/2 ]^21=[599074585-267914293√5]/2
(2) a=(3-√5)/2 1/a=2/(3-√5)=(3+√5)/2
a²+1/a^21=[(3-√5)/2]^2+[(3+√5)/2 ]^21=[599074585+267914293√5]/2
估计题应该是a²+1/a²+1
a²-3a+1=0
(1)a-3+1/a=0 1/a=3-a 1/a²=(3-a)²=9-6a+a²=9-6a+3a-1=8-3a
(2)a²=3a-1
a²+1/a²+1=3a-1+8-3a+1=8