A vector ` vec r\ ` is inclined to x-axis at `45^0` and y-axis at `60^0dot` If `| vec r|=8` units, find ` vec rdot`

Explanation

Неге, `alpha=45^{circ}, beta=60^{circ}, gamma=theta (say)`

`l=cos alpha`

`=cos 45^{circ}`

`l=frac{1}{sqrt{2}}`

`m=cos alpha`

`=cos 45^{circ}`

`m=frac{1}{2}`

`n=cos theta` Now, substituting `l, m, n` in

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