Question

if m(2i+j-k) is a unit vector then the value of m is...

Answer 1

Check the attachment

Answer 2

As given vector is a unit vector then,

${(2m)}^{2} + {m}^{2} + {( - m)}^{2} = {( 1)}^{2}$

$4 {m}^{2} + {m}^{2} + {m}^{2} = 1$

$6 {m}^{2} = 1$

${m}^{2} = \frac{1}{6}$

$m \: = \frac{1}{ \sqrt{6} }$

$m \: = \frac{ \sqrt{6} }{6}$