Question

Locus of the point p ,for which op represents a vector with direction cosines cos alpha,cos beta,cos gamma such that cos alpha =1/2

Answer 1

Let P(x1, y1, z1) and Q(x2, y2, z2) be two given points. The distance between these points is given by

PQ √(x2 – x1)2 + (y2 – y1)2 + (z2 – z1)2

The distance of a point P(x, y, z) from origin O is

OP = √x2 + y2 + z2