((y+dfrac {1)(2))}^2=dfrac (3)(4) D. ((y-dfrac {1)(2))}^2=dfrac (3)(4)

下列选项中曲面dfrac ({x)^2}(4)+dfrac ({y)^2}(1)+dfrac ({z)^2}(9)=3上点dfrac ({x)^2}(4)+df

求椭球面dfrac ({x)^2}(2)+dfrac ({y)^2}(3)+dfrac ({z)^2}(4)=1上点dfrac ({x)^2}(2)+dfrac

设l为椭圆dfrac ({x)^2}(4)+dfrac ({y)^2}(3)=1，其周长记为a，则dfrac ({x)^2}(4)+dfrac ({y)^2}(

直线-1=dfrac (y+3)(-2)=z-4与直线-1=dfrac (y+3)(-2)=z-4的夹角为( )-1=dfrac (y+3)(-2)=z-4-1

B. dfrac {1)(2) . C. dfrac (2)(3) . D. dfrac (3)(4)

2.求曲线 ^dfrac (2{3)}+(y)^dfrac (2{3)}=(a)^dfrac (2{3)} 在点 (dfrac (sqrt {2)}(4)a,d

2.求曲线 ^dfrac (2{3)}+(y)^dfrac (2{3)}=(a)^dfrac (2{3)} 在点 (dfrac (sqrt {2)}(4)a,d

直线dfrac (x-1)(2)=dfrac (y)(-1)=dfrac (z-2)(3)-|||-__与直线dfrac (x-1)(2)=dfrac (y)(

求曲线^dfrac (2{3)}+(y)^dfrac (2{3)}=(a)^dfrac (2{3)},在点^dfrac (2{3)}+(y)^dfrac (2{

[题目]-|||-求曲线 ^dfrac (2{3)}+(y)^dfrac (2{3)}=(a)^dfrac (2{3)} 在点 (dfrac (sqrt {2)