(1):若;2/(x^2-x+1)=1/x,求x^2/(x^4-1)的值.(2):y=√17－x,xy=3,求x^3+y^3的值 _数学解答

(1):若;2/(x^2-x+1)=1/x,求x^2/(x^4-1)的值.(2):y=√17－x,xy=3,求x^3+y^3的值两题求解,过程. 11 分钟

人气：214 ℃　时间：2020-06-16 13:29:11

解答

(1):若;2/(x^2-x+1)=1/x2x/(x²-x+1)=12/(x-1+1/x)=1x-1+1/x=2x+1/x=3x²+2+1/x²=9x²+1/x²=7(x-1/x)²=5x-1/x=±√5所以x²/(x^4-1)=1/(x²-1/x²)=1/(x+1/x)(x-1/x)=± 1/(...