二维连续型随机变量求期望先对谁积分,都是先对y求积分后对x求积分嘛 二维连续型随机变量(x,y)的联合分布求概率密度时如何确定x...
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绛旓細1)E(X)=E[E(X|Y)],灏辨槸鍏堝鏌怸鍊间笂鐨X绉垎鍐嶅鍏ㄥ眬绉垎 2)浣犳眰鍑洪潰绉,鍏跺掓暟灏辨槸浜.3)E(Z)=E(2X+Y)=2E(X)+E(Y)涔嬪悗濡1璁$畻X鍜孻鏈熸湜,D(Z)=E(Z^2)-E(Z)^2,鏂规硶鍚屼笂,鍙槸璁$畻鏈熸湜鎵涔樼殑涓嶆槸x,鑰屾槸x^2
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绛旓細杩炵画鎬浜岀淮闅忔満鍙橀噺鏁板鏈熸湜 鎴戞潵绛 1涓洖绛 #鐑# 涓轰粈涔堝瓟瀛愬儚浼氶洉鍒诲湪缇庢渶楂樻硶闄鐨闂ㄦィ涔嬩笂?闈掑窞鍚т娇鑰5974 2021-02-03 路 瓒呰繃66鐢ㄦ埛閲囩撼杩嘥A鐨勫洖绛 鐭ラ亾绛斾富 鍥炵瓟閲:129 閲囩撼鐜:100% 甯姪鐨勪汉:32.4涓 鎴戜篃鍘荤瓟棰樿闂釜浜洪〉 鍏虫敞 ...
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绛旓細瀵逛簬浜岀淮杩炵画鍙橀噺鐨勫垎甯冨嚱鏁癋(x锛寉)锛屼竴鑸簲鐢ㄥ叾姒傜巼瀵嗗害鍑芥暟f(x锛寉)鐨勫畾绉垎姹傝В锛涘浜庨潪杩炵画鍙橀噺锛岄渶瑕佸垎鍒疮鍔犳眰寰椼愪笌涓缁闅忔満鍙橀噺鐨姹傛硶鐩镐豢銆戙傗埓鏈涓紝褰搙鈭(0,鈭)銆亂鈭(0锛屸垶)鏃讹紝鍒嗗竷鍑芥暟F(x锛寉)=鈭(-鈭烇紝x)du鈭(-鈭,y)f(u锛寁)dv=鈭(0锛寈)du鈭(-0锛寉)2e^(-2u-v...