若x+1/x=3,则x^2+1/x^2=多少

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/29 02:11:17
若x+1/x=3,则x^2+1/x^2=多少若x+1/x=3,则x^2+1/x^2=多少若x+1/x=3,则x^2+1/x^2=多少若x+1/x=3,则x^2+1/x^2=(x+1/x)^2--2=3

若x+1/x=3,则x^2+1/x^2=多少
若x+1/x=3,则x^2+1/x^2=多少

若x+1/x=3,则x^2+1/x^2=多少
若x+1/x=3,则 x^2+1/x^2=(x+1/x)^2--2
=3^2--2
=9--2
=7.

x+1/x=3,
两边平方
x^2+2+1/x^2=9x^2+1/x^2=7

5