The direction cosines of the line $x-y+2 z=5$ and $3 x+y+z=6$ are

20 is divided into two parts so that the product of the cube of one part and the square of the other part is maximum, then these two parts are

The acute angle between the diagonals of a parallelogram whose vertices are $\mathrm{A}(2,-1)$, $B(0,2), C(2,3)$ and $D(4,0)$ is

The shortest distance between the line $y-x=1$ and the curve $x=y^2$ is