如果x方-2x-1=0,求x方/(x的4次-3x方+1)等wo要

Question

如果x方-2x-1=0,求x方/(x的4次-3x方+1) 等
wo 要

Answer 1

数学之美团为你解答
x² - 2x - 1 = 0
同除以 x
x - 2 - 1/x = 0
x - 1/x = 2
平方
x² - 2 + 1/x² = 4
x² - 3 + 1/x² = 3
(x⁴ - 3x² +1)/x² = 3
x²/(x⁴-3x²+1) = 1/3