已知函数f(x)满足方程f(x)f(x)2f(x)0及()()2xfxfxe,(I)求f(x)的表达式 (II)求曲线220()()dxyfxftt的拐点.
Hefellasleepimmediatelylastnight;hemust________(be)verytired.
________fromtheoccasionallatenightparty,ourneighborsareveryquiet.
设随机变量(X,Y)服从二维正态分布N(0,0;1,4;-1/2),随机变量中服从标准正态分布且与X独立的是()
He________methathedecidedtoleaveonMonday.
