Calculating Magnitude and Direction Cosines of a Vector in Physics

[tdusffx]

I just started physics this year and having a difficult time, lol.

anyways, my question is:

suppose I was given a vector A, and A has x, y, z components of 4,6,3

How would I find its magnitude of A and the cosines of the angles that makes B?

 

[bel]

It's like finding the length of a diagonal of a rectangle of length, breadth and depth of 4, 6, and 3 respectively, by the Pythagoras's theorem. And what's B?

 

[tdusffx]

i'm sorry, I meant what are the angles that make vector A, sorry.

 

[tdusffx]

also, I'm just wondering why I can't apply the formula Magnitude A = sqrt (x^2, y^2, z^2)

 

[robphy]

By the way, your "vector" questions are MATH problems.
There's no physics yet. (Physics is not to blame.)


Are you looking for the "direction cosines"?
http://www.netcomuk.co.uk/~jenolive/vect7.html

 

[tdusffx]

I just want to know if I use the |A| = sqrt (x^2 + y^2 + z^3)

 

[tdusffx]

or the rectangular length like bel has mentioned above.

 

[Archduke]

I just want to know if I use the |A| = sqrt (x^2 + y^2 + z^3)

Yep, you can.

 

[tdusffx]

hmm, ok thank you guys for the help.