已知x2+3x+1=0,求(1)x+1/x,(2)x2+1/x2+2x+2/x的值

来源:学生作业帮助网 编辑:六六作业网 时间:2024/07/04 21:59:42
已知x2+3x+1=0,求(1)x+1/x,(2)x2+1/x2+2x+2/x的值已知x2+3x+1=0,求(1)x+1/x,(2)x2+1/x2+2x+2/x的值已知x2+3x+1=0,求(1)x+

已知x2+3x+1=0,求(1)x+1/x,(2)x2+1/x2+2x+2/x的值
已知x2+3x+1=0,求(1)x+1/x,(2)x2+1/x2+2x+2/x的值

已知x2+3x+1=0,求(1)x+1/x,(2)x2+1/x2+2x+2/x的值
等式两边同除以x
x+3+1/x=0
x+1/x=-3
x²+1/x²+2x+2/x
=(x+1/x)²-2+2(x+1/x)
=(-3)²-2+2(-3)
=9-2-6
=1