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已知X^2-4x+1=0,求x^4+1/x^4的值详细步骤

2018-02-07 11:18:42s***
详细步骤已知X^2-4x+1=0,求x^4+1/x^4的值详细步骤:解:x²-4x+1=0 ===> x-4+1/x=0 ===> x+1/x=4 (x+1?

最佳回答

  • 解:x²-4x+1=0 ===> x-4+1/x=0 ===> x+1/x=4 (x+1/x)^2=x²+2+1/x²=16 ===> x²+1/x²=14 (x²+1/x²)²=x^4+2+1/x^4=196 ===> x^4+1/x^4=194
    2018-02-07 23:18:42
  • 因为x不等于0,所以两边都除以x,得 x-4+1/x=o,所以x+1/x=4, 两边平方得x^2+1/x^2=14 两边再平方得x^4+1/x^4=194.
    2018-02-08 03:18:42
  • 很赞哦! (212)