# Math Help - Dot or Cross product?

1. ## Dot or Cross product?

If i need to find the angle between two vectors a, b, which method should i use? dot or cross product?

And in when do i use dot/cross product to find the angle?

2. Hello,

The dot product uses the cosine of the angle between the vectors and the cross product uses the sine of the angle
So it depends/

3. Originally Posted by MilK
If i need to find the angle between two vectors a, b, which method should i use? dot or cross product?
Well,given a choice, I'd prefer dot product. Computing it is simpler .

4. Originally Posted by Isomorphism
Well,given a choice, I'd prefer dot product. Computing it is simpler .
Plus, dot product can be used in 2D space, not cross product

5. so if i want to find the angle, i can use either dot or cross product? which will give me the same result?

6. Yes although I agree that using the dot product would in general be more easier. If you were given two vectors, would you rather find their scalar or cross product?

7. of cos dot