A.2mmB.4mmC.8mmD.4cm
A.權(quán)陣中主對(duì)角線元素為各隨機(jī)變量的權(quán)B.權(quán)陣中主對(duì)角線元素為各隨機(jī)變量的協(xié)因數(shù)C.若權(quán)陣為對(duì)角陣時(shí),其主對(duì)角線元素即為各隨機(jī)變量的權(quán)D.若權(quán)陣為對(duì)角陣時(shí),其主對(duì)角線元素即為各隨機(jī)變量的協(xié)因數(shù)
A.3*3的方陣B.3*3對(duì)稱方陣C.3*3單位陣D.3*3的對(duì)角陣