搜题请搜索小程序“爱下问搜题”
问题 解答题

已知关于x的一元二次方程2x2-（2m+1）x+m=0根的判别式是9，求m的值及方程的根．

答案

由题意得：（2m+1）2-4×2m=9，

解得m=2或-1，

当m=2时，原方程化为：2x2-5x+2=0，

解得x=2或0.5；

当m=-1时，原方程化为：2x2-x-1=0，

解得x=1或-0.5；

单项选择题

东宫之主到底谁是主？（）

A.皇上

B.皇后

C.太子
查看答案
单项选择题

For each blank，choose the best answer from the four choices and write down on the answer sheet．

(1) is a protocol that a host uses to inform a router when it joins or leaves an Internet multicast group．

(2) is an error detection code that most data communication networks use．

(3) is an interior gateway protocol that uses a distance vector algorithm to propagate routing information．

(4) is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non -periodic basis over a range of media.

(5) is an identifier of a web page.

4（）

A．ADSL

B．ATM

C．Frame Relay

D．DDN
查看答案