1. ranyai12

2. oldrin.bataku

Remember that the magnitude $$|\vec{a}|$$ and dot product $$\vec{a}\cdot\vec{b}$$ both operate on *vector(s)* to yield a *scalar*.

3. ranyai12

also just to double check, you cant multiply a vector and a scalar together right

4. ranyai12

so would first one be valid

5. ranyai12

im thinking its valid, valid,invalid, valid

6. ranyai12

am i right?

7. ranyai12

@oldrin.bataku

8. oldrin.bataku

The last is valid? Are you sure? It's a dot product between a scalar and vector.

9. ranyai12

oh no yr right its invalid

10. ranyai12

thank you!:)