已知实数X满足X²+1/X²+X+1/X=0,那么X+1/X的值是?A.1或-2B.-1或2C.1D.-2要详细,求大神帮忙!

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/09 18:32:02
已知实数X满足X²+1/X²+X+1/X=0,那么X+1/X的值是?A.1或-2B.-1或2C.1D.-2要详细,求大神帮忙!

已知实数X满足X²+1/X²+X+1/X=0,那么X+1/X的值是?A.1或-2B.-1或2C.1D.-2要详细,求大神帮忙!
已知实数X满足X²+1/X²+X+1/X=0,那么X+1/X的值是?
A.1或-2
B.-1或2
C.1
D.-2
要详细,求大神帮忙!

已知实数X满足X²+1/X²+X+1/X=0,那么X+1/X的值是?A.1或-2B.-1或2C.1D.-2要详细,求大神帮忙!
X²+1/X²+X+1/X=0
(X+1/X)²-2+X+1/X=0
(X+1/X)²+(X+1/X)-2=0
(X+1/X+2)(X+1/X-1)=0
X+1/X+2=0或X+1/X-1=0
X+1/X=-2或X+1/X=1

过程同1楼
但是1这个根舍去
D
x+1/x=1
x^2+1=x
x^2-x+1=0
x无解的

设X+1/X=y
则:X²+1/X²=(X+1/X)²-2
X²+1/X²+X+1/X=Y^2+Y-2=0
解得:Y=1或-2