简答题:随机变量X的分布律为 <br /> <img src="http://www.weimei168.com/uploads/202208/16122385408371.png" width="188" height="74" /><br /> 记Y=X2． <br /> 求：(1)D(X)，D(Y)； <br /> (2)<img src="http://www.weimei168.com/uploads/202208/161223854616121.png" width="35" height="29" />．