AP EAPCET 17th May 2023 Shift 1 Solved Paper

Coordinate planes and the planes π1,π2,π3 which are respectively parallel to YZ, ZX, XY planes at distances a, b, c, form a rectangular parallelepiped. d1 is a diagonal of the face on XY-plane not passing through origin and d2 is diagonal of plane π2 coterminous with d1. If none of the coordinates of the vertices of the parallelepiped are negative and angle between d1 and d2 is θ, then cos‌θ=