Question

Find the values of p so the line (1-x)/3 =(7y-14)/2p=(z-3)/2   and (7-7x)/3p =(y-5)/1 =(6-z)/5 are at  right angles.

Answer 1

The given equations can be written in the standard form as

Two lines with direction ratios, a₁, b₁, c₁ and a₂, b₂, c₂, are perpendicular to each other, if a₁a₂ + b₁ b₂ + c₁c₂ = 0