已知2m²-√17m+2=0.(1)求m²+m²分之1的值;(2)求m-m分之1的值.
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/24 18:27:47
![已知2m²-√17m+2=0.(1)求m²+m²分之1的值;(2)求m-m分之1的值.](/uploads/image/z/1811350-46-0.jpg?t=%E5%B7%B2%E7%9F%A52m%26%23178%3B%EF%BC%8D%E2%88%9A17m%EF%BC%8B2%EF%BC%9D0.%281%29%E6%B1%82m%26%23178%3B%EF%BC%8Bm%26%23178%3B%E5%88%86%E4%B9%8B1%E7%9A%84%E5%80%BC%EF%BC%9B%EF%BC%882%EF%BC%89%E6%B1%82m%EF%BC%8Dm%E5%88%86%E4%B9%8B1%E7%9A%84%E5%80%BC.)
已知2m²-√17m+2=0.(1)求m²+m²分之1的值;(2)求m-m分之1的值.
已知2m²-√17m+2=0.(1)求m²+m²分之1的值;(2)求m-m分之1的值.
已知2m²-√17m+2=0.(1)求m²+m²分之1的值;(2)求m-m分之1的值.
两边除以2m得
m-√17/2+1/m=0
m+1/m=√17/2
两边平方得
m²+2+1/m²=17/4
∴m²+1/m²=9/4
两边再减去2得
m²-2+1/m²=1/4
(m-1/m)²=1/4
∴m-1/m=1/2或-1/2