A vector ` vec r` is inclined at equal angle to the three axes. If the magnitude of ` vec r` is `2 sqrt3,\ ` find ` vec rdot`

Explanation

We have, `vec(r) =2 sqrt{3}`

Since `vec{r}` is equally inclined to the three axes, direction cosines of the unit
vector `vec{r}` will be the same.

`i.e., l=m=n.`

Now we know that.

` l^{2}+m^{2}+n^{2}=1 `

`Rightarrow l^{2}+l^{2}+l^{2}=1`

`Rightarrow quad l^{2}=frac{1}{3} `

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