2.已知
求(a+b-c)²。3.设x>0,且
求
的值。4.已知实数x满足
求
的值。
计算:(3x+y+2)(3x-y-2).计算:(3x+y+2)(3x-y-2).
计算:(3x+y+2)(3x-y-2).计算:.
已知函数 =(x)^3y+3(x)^2(y)^2-x(y)^3 ,则 =(x)^3y+3(x)^2(y)^2-x(y)^3 ( ) A =(x)^3y+3
A (x,y)=(x)^3-6(x)^2y-3x(y)^2+2(y)^3 . B (x,y)=(x)^3-6(x)^2y-3x(y)^2+2(y)^3 . C
3.已知两个线性变换-|||- ) (x)_(1)=2(y)_(1)+(y)_(3), (x)_(2)=-2(y)_(1)+3(y)_(2)+2(y)_(3)
10.已知线性变换-|||- ) (x)_(1)=2(y)_(1)+2(y)_(2)+(y)_(3) (x)_(2)=3(y)_(1)+(y)_(2)+5(y
3.已知两个线性变换-|||- ) (x)_(1)=2(y)_(1)+ (y)_(3) (x)_(2)=-2(y)_(1)+3(y)_(2)+2(y)_(3
以下函数数中,是(x,y)=(x)^3-3x(y)^2-y的共轭调和函数的是(x,y)=(x)^3-3x(y)^2-y (x,y)=(x)^3-3x(y)^2-
15.求下列函数的极值.-|||-(1) (x,y)=(x)^3-4(x)^2+2xy-(y)^2+3 ;-|||-(2) (x,y)=3xy-(x)^3-(y
求下列函数的极值点: (1)z=3axy-x^3-y^3(a>0); (2)z=x^2-xy+y^2-2x+y; (3)z=e^2x(x+y^2+2y).8.