Direction cosines of a line which makes equal angles with co-ordinate axis are1\(\pm (1,1,1)\)2\(\pm \left(\frac{1}{\sqrt{3}},\frac{1}{\sqrt{3}},\frac{1}{\sqrt{3}}\right)\)3\(\pm \left(\frac{1}{3},\frac{1}{3},\frac{1}{3}\right)\)4\(\pm \left(-\frac{1}{\sqrt{3}},-\frac{1}{\sqrt{3}},-\frac{1}{\sqrt{3}}\right)\)Answer & explanation+Correct answer: option 2\(\cos^{2}\alpha+\cos^{2}\alpha+\cos^{2}\alpha=1\)
