determine if the following statements are true or false, and explain why. (a) if u, v, and w are all vectors in r3, the calculation u ·v ·w results in a vector. (b) if u, v, and w are all vectors in r3, then the volume of the parallelepiped generated by these three vector is ∥u ×v ×w∥ (c) there is no vector v where ⟨1, −2, 1⟩×v