1. anonymous

2. anonymous

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

3. anonymous

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

4. anonymous

so would first one be valid

5. anonymous

im thinking its valid, valid,invalid, valid

6. anonymous

am i right?

7. anonymous

@oldrin.bataku

8. anonymous

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

9. anonymous

oh no yr right its invalid

10. anonymous

thank you!:)