# Homework Help: How to solve this question?

1. Jul 26, 2008

### gearstrike

how to solve this question??

A vector is given by R=2i + j + 3k.
find (a) the magnitude of the x,y,z components,
(b) the angels between R and the x,y and z axes..

2. Jul 26, 2008

### arunbg

Re: how to solve this qouestion??

How much do you know about vectors? These questions are fairly basic.

3. Jul 26, 2008

### gearstrike

Re: how to solve this qouestion??

punderq arunburg.....m asking u to do dat question...not to comment my question...u little funky...challenge u to answer my question .....

4. Jul 26, 2008

### Defennder

Re: how to solve this qouestion??

Please read the forum rules. You are expected to show your work before anyone can help. And no, your questions are not "challenging" at all.

5. Jul 26, 2008

### Redbelly98

Staff Emeritus
Re: how to solve this qouestion??

gearstrike, we only help after you've shown us some attempt at trying to solve it yourself.

In your class or textbook, haven't they discussed the components of a vector? And something (anything) about angles & vectors?

6. Jul 26, 2008

### rocomath

Re: how to solve this qouestion??

lmao!!! Funny talking little funky :p

7. Jul 27, 2008

### gearstrike

Re: how to solve this qouestion??

im sory guys,
im really dont know about this question..
basicly,im bad in basic..can you guys help me.?

8. Jul 27, 2008

### Defennder

Re: how to solve this qouestion??

Well, to start off, what do you understand by the "magnitude of the x,y,z components"? And for the second, what have you learnt about the dot product that you can apply here?

9. Jul 28, 2008

### gearstrike

Re: how to solve this question??

ermm,
what i know abaout magnitude x,y and z is equal to = i + j + k.

10. Jul 28, 2008

### HallsofIvy

Re: how to solve this question??

That makes no sense at all! The magnitude of a vector is its length- a number, not a vector. The magnitude of the vector $x\vec{i}+ y\vec{j}+ z\vec{k}$ is $\sqrt{x^2+ y^2+ z^2}$.

To find the "direction angles", the angles a vector makes with the x, y, and z axes, you find a unit vector in that direction. The components of a unit vector are the "direction cosines": a unit vector is always of the form $cos(\theta)\vec{i}+ cos(\phi)\vec{j}+ cos(\psi)\vec{k}$ where $\theta$, $\phi$, and $\psi$ are the angles the vector makes with the x, y, and z axes respectively.

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