求平面2x-y+2z-8=0及x+y+z-10=0夹角弦.

求平面2x-y+2z-8=0及x+y+z-10=0夹角弦. 已知：x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值 求直线2x+2y-z=1 3x+8y+z=6与平面2x+2y-z+6=0的夹角 求过点(1,1,1)且垂直于平面x-y+z=7及3x+2y-12z+5=0的平面方程 (x*x+2)(y*y+4)(z*z+8)=64xyz,求x,y,z 微积分：空间解析几何简介求通过原点且垂直于平面x-y+z-7=0及3x+2y-12z+5=0的平面方程答案是2x+3y+z=0 求锥面z=根号下x^2+y^2、圆柱面x^2+y^2=1及平面z=0所围立体体积.求解,高等数学 求柱面x^2+y^2=1,平面x+y+z=3及z=0围成立体的体积 已知x、y、z满足方程组：x+y-z=6；y+z-x=2；z+x-y=0 求x、y、z的值 已知X.Y.Z满足方程组,X+y-Z=6y+z-x=2z+x-y=0求X.Y.Z的值 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 求曲面z=x^2 y^2及平面z=4所围成立体的体积求曲面z=x^2+y^2及平面z=4所围成立体的体积 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 求平面x-2y+2z-8=0和x+z-6=0的夹角 1998(x-y)+1989(y-z)+1990(z-x)=0,1998^2(x-y)+1989^2(y-z)+1990^2(z-x)=1989,求z-y 已知4x-3y+z=0,x+2y-8z=0,xyz不等于0,求x+y-z/x-y+2z的值 已知方程组x+2y-z=0,2x-y+8z=0,求x*x+y*y+z*z/xy+yz的值