If ` vec a` is a non zero vector a magnitude `' a^(prime)\ a n d\ lambda` is a non a zero scalar, then `lambda\ vec a` is a unit vector if a.`lambda=1` b. `lambda=-1` c. `a-|lambda|` d. `a=1/(|lambda|)`

Explanation

vector `|a|=a`

`Given : lambda vec{a}` is a unit vectors

`Rightarrow|lambda vec{a}|=1 `

`Rightarrow|lambda||vec{a}|=1 `

`Rightarrow|lambda| a=1 `

`Rightarrow quad a=frac{1}{|lambda|}`

Hence option (d), is correct.