JEE Advanced 2023 Paper 1Question 261
Let $Q$ be the cube with the set of vertices $\{(x_1,x_2,x_3)\in\mathbb{R}^3: x_1,x_2,x_3\in\{0,1\}\}$. Let $F$ be the set of all twelve lines containing the diagonals of the six faces of the cube $Q$. Let $S$ be the set of all four lines containing the main diagonals of the cube $Q$; for instance, the line passing through the vertices $(0,0,0)$ and $(1,1,1)$ is in $S$. For lines $\ell_1$ and $\ell_2$, let $d(\ell_1,\ell_2)$ denote the shortest distance between them. Then the maximum value of $d(\ell_1,\ell_2)$, as $\ell_1$ varies over $F$ and $\ell_2$ varies over $S$, is
3D Geometry