已知(a2+b2+1)2=4,求a2+b2的值。
解:a2+b2+1=±2
∴a2+b2=1, a2+b2=-3
∵a2≥0,b2≥0
∴a2+b2≥0
∴a2+b2=1
When creating intervals around the mean to indicate the dispersion of outcomes, which of the following measures is the most useful The()
A. variance.
B. median.
C. standard deviation.
假定建立了一个工程,该工程包括两个窗体,其名称(Name属性)分别为Form1和Form2,启动窗体为 Form1。在Form1中画一个命令按钮Command1,程序运行后,要求当单击该命令按钮时,Form1窗体消失,显示窗体Form2,请将程序补充完整。 Private Sub Command1_Click() ______Me Form2.______ End Sub