Find the value of p such that the lines\(\frac{x-1}{3}=\frac{y+4}{p}=\frac{z-9}{1}\) \(\frac{x+2}{1}=\frac{y-3}{1}=\frac{z-7}{-2}\) are at right angles to each other.

MCQs on direction cosines and line ratios, line equation in space, angle and shortest distance b/w two lines, plane, angle b/w two planes, two lines coplanarity, point distance from plane, angle b/w line and plane.