You are Here: Home >< Maths

# FP3 - Vectors watch

1. Hi I was wondering if someone could explain to me the dot product of two vectors and how to go about finding A.B?

I have attached a question which I found, but it doesn't follow the formula of A.B so I was confused as to how to go about these questions and was wondering if someone could explain it??
Attached Files
2. maths.docx (174.3 KB, 49 views)
3. if

https://math.dartmouth.edu/archive/m...m9lect1031.pdf

the b) and c) are for the cross product and the area of a parallelogram formed by 2 vectors.
4. The formula is:

This is exactly what has happened in part a. So I'm not sure what you mean by it doesn't follow the formula?

Do you mean it doesn't follow:
?
5. (Original post by rayquaza17)
The formula is:

This is exactly what has happened in part a. So I'm not sure what you mean by it doesn't follow the formula?

Do you mean it doesn't follow:
?

Yes that's what I meant. It didn't follow the second formula. Am I correct in presuming, that if an angle has not been indicated I use

And when an angle is indicated I use

Sorry this may sound stupid it's just vectors are my least favorite topic in maths!
6. (Original post by Sapphiresmith)
Yes that's what I meant. It didn't follow the second formula. Am I correct in presuming, that if an angle has not been indicated I use

And when an angle is indicated I use

Sorry this may sound stupid it's just vectors are my least favorite topic in maths!
That's correct.

Don't worry, I hated vectors at a level too. Now I'm at uni though, they're one of my favourite things.

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: January 11, 2015
Today on TSR

### Edexcel C2 Core Unofficial Markscheme!

Find out how you've done here

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams