# Homework Help: Equation that equates the magnitude of a vector

1. Oct 14, 2004

### Crauven

I am in 11th grade, in AP Physics... its calculus based, and I have never had calculus so its confusing. At this time I cannot find the equation that equates the magnitude of a vector off of an ai+bj equation. Does anyone know?

2. Oct 14, 2004

### Pyrrhus

Draw a vector, and mark his components, what figure does it look to you??

3. Oct 14, 2004

### Crauven

... thats not what my question was. I need to know how to find the magnitude for a vector before my test today during fifth period...

4. Oct 14, 2004

### Pyrrhus

It makes a Triangle, but an specific type of triangle, the one you can apply pythagoras theorem.

a is a component of the vector, and b is another component of the vector.
Both of these are cathetes(sp?) and the vector's magnitude is the hypotenuse.

5. Oct 14, 2004

### Crauven

Oh I understand what you were saying. So its just, as per the ai+bj, a^2+b^2=the vector side^2?

And is it just me or does three dimensional vector graphing really blow? :)

Thank you.

6. Oct 14, 2004

### Pyrrhus

It's the vector is tridimensional, it's the same for the magnitude, the sum of the squares of the components is equal to the vector's magnitude squared.

Last edited: Oct 14, 2004
7. Oct 14, 2004

### Crauven

Ahah! I wont fail my test! Thanks for the help.

8. Dec 5, 2004

### jai6638

hey.. i hope to take AP physics B next year but i woudnt have done a calclus course by then... is the course manageable without basic knowledge of calculus?

thanks