求函数 =x(y)^2+(z)^3-xyz 在点(1,1,2)处沿方向角为-|||-alpha =dfrac (pi )(3), beta =dfrac (pi )(4), =dfrac (pi )(3) 的方向的方向导数.

设(X,Y)的分布函数为(x,y)=dfrac (1)({pi )^2}(dfrac (pi )(2)+arctan dfrac (x)(2))(dfrac (

函数 u=x^2+2y+3z^3 在点 (1,-1,1) 处沿方向角 alpha=(pi)/(4), beta=(pi)/(3), gamma=(pi)/(3)

3.要使函数φ(x )= ,dfrac {pi )(2)] (B)[π,2π] (C) [ 0,dfrac (pi )(2)] (D) [ dfrac

已知函数 (x)=dfrac (1)(2)sin (2x-dfrac (pi )(3)) x∈R,-|||-(1)求f(x)的最小正周期;-|||-(2)求f(

(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (|x|sin x)(1+{cos )^3x}dx=(int )_(-

( (int )_(dfrac {pi )(4)}^dfrac (pi {3)}dfrac (x)({sin )^2x}dx ;

(3) (int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx= () .-|||-(A) dfrac (pi )(8)+

设=(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (sin x)(1+{x)^2}(cos )^4xdx, =(in

2.计算下列定积分:-|||-(1) (int )_(dfrac {pi )(3)}^pi sin (x+dfrac (pi )(3))dx;-|||-(2)

1.计算下列定积分:-|||-(1) (int )_(dfrac {pi )(3)}^pi sin (x+dfrac (pi )(3))dx ;-|||-(2)