The angle between the lines whose direction cosines satisfy and is

MATHEMATICS · Single correct · CBSE · Mathematics · Three-Dimensional Geometry · Three-Dimensional Geometry

Problem

The angle between the lines whose direction cosines satisfy

l+m+n=0

and

l^2=m^2+n^2

is (1)

\frac{\pi}{3}

(2)

\frac{\pi}{4}

(3)

\frac{\pi}{6}

(4)

\frac{\pi}{2}