已知一元二次方程x²-x-3=0的较小根为x1的估计正确的是( )a.-2<x1<-1 b.-3<x<-2 c.2<x1<3 d.-1<x1<0
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![已知一元二次方程x²-x-3=0的较小根为x1的估计正确的是( )a.-2<x1<-1 b.-3<x<-2 c.2<x1<3 d.-1<x1<0](/uploads/image/z/10917550-46-0.jpg?t=%E5%B7%B2%E7%9F%A5%E4%B8%80%E5%85%83%E4%BA%8C%E6%AC%A1%E6%96%B9%E7%A8%8Bx%26%23178%3B-x-3%3D0%E7%9A%84%E8%BE%83%E5%B0%8F%E6%A0%B9%E4%B8%BAx1%E7%9A%84%E4%BC%B0%E8%AE%A1%E6%AD%A3%E7%A1%AE%E7%9A%84%E6%98%AF%28+%29a.-2%EF%BC%9Cx1%EF%BC%9C-1+b.-3%EF%BC%9Cx%EF%BC%9C-2+c.2%EF%BC%9Cx1%EF%BC%9C3+d.-1%EF%BC%9Cx1%EF%BC%9C0)
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已知一元二次方程x²-x-3=0的较小根为x1的估计正确的是( )a.-2<x1<-1 b.-3<x<-2 c.2<x1<3 d.-1<x1<0
已知一元二次方程x²-x-3=0的较小根为x1的估计正确的是( )
a.-2<x1<-1 b.-3<x<-2 c.2<x1<3 d.-1<x1<0
已知一元二次方程x²-x-3=0的较小根为x1的估计正确的是( )a.-2<x1<-1 b.-3<x<-2 c.2<x1<3 d.-1<x1<0
A
先通过计算得出x1=-1.302775638,
x2=2.302775638,由选项可得,答案为A