## spndsh Group Title when do you use the dot product? one year ago one year ago

1. TuringTest Group Title

the most simple answer I can give you to that very general question when you want to determine how parallel two lines are, or the angle between them

2. spndsh Group Title

ok, how do you use dot product to find a vector projection?

3. TuringTest Group Title

Given two vector $$\vec a$$ and $$\vec b$$ the projection of $$\vec b$$ onto $$\vec a$$ is given by$\text{proj}_{\vec a}\vec b={\vec a\cdot\vec b\over\|\vec a\|^2}\vec a$

4. TuringTest Group Title

where $\|\vec a\|$ is the magnitude of $$\vec a$$

5. spndsh Group Title

oh, thanks so much!

6. TuringTest Group Title

welcome!