Unit vectors please check my answer

[jhosamelly]

Homework Statement

if \vec{e_{1}} = 5\hat{i} - 3\hat{j} + 2\hat{k} what is the unit vector \hat{e_{1}}

Homework Equations

The Attempt at a Solution

here is my answer,, please confirm if I'm correct.

|\hat{e_{1}}| = \sqrt{\vec{e_{1}} . \vec{e_{1}}}
|\hat{e_{1}}| = \sqrt{(5\hat{i} - 3\hat{j} + 2\hat{k}) . (5\hat{i} - 3\hat{j} + 2\hat{k})}
|\hat{e_{1}}| = \sqrt{(5\hat{i}) . (5\hat{i}) + (-3\hat{j}) . (-3\hat{j}) + (2\hat{k}) . (2\hat{k})}
|\hat{e_{1}}| = \sqrt{(25+9+4)}
|\hat{e_{1}}| = \sqrt{38}


\hat{e_{1}} = \frac{5\hat{i} - 3\hat{j} + 2\hat{k}}{\sqrt{38}}

am i correct? Please check

 

[SammyS]

Homework Statement

if \vec{e_{1}} = 5\hat{i} - 3\hat{j} + 2\hat{k}

Homework Equations

The Attempt at a Solution

That's not a unit vector.

Please state the problem you're trying to solve.

 

[jhosamelly]

That's not a unit vector.

Please state the problem you're trying to solve.

sorry i wasn't finished editing yet earlier.. please check my solution now. Thanks

 

[SammyS]

The Attempt at a Solution

here is my answer,, please confirm if I'm correct.

|\hat{e_{1}}| = \sqrt{\vec{e_{1}} . \vec{e_{1}}}
|\hat{e_{1}}| = \sqrt{(5\hat{i} - 3\hat{j} + 2\hat{k}) . (5\hat{i} - 3\hat{j} + 2\hat{k})}
|\hat{e_{1}}| = \sqrt{(5\hat{i}) . (5\hat{i}) + (-3\hat{j}) . (-3\hat{j}) + (2\hat{k}) . (2\hat{k})}
|\hat{e_{1}}| = \sqrt{(25+9+4)}
|\hat{e_{1}}| = \sqrt{38}


\hat{e_{1}} = \frac{5\hat{i} - 3\hat{j} + 2\hat{k}}{\sqrt{38}}

am i correct? Please check

Yes. That is correct .

 

[jhosamelly]

Thanks.. Can you please check my other question.. I really appreciate it! Thanks again.