Answer
(a) False.
Because, $$\|\mathbf{v}\|=\sqrt{|v_{1}^2+v_{2}^2+v_{3}^2+\cdots+v_{n}^2}.$$
(b) False.
Because, $$\mathbf{u} \cdot \mathbf{v}=u_{1} v_{1}+ u_{2} v_{2}+ u_{3} v_{3}+ \dots, u_{n} v_{n}.$$
Work Step by Step
(a) False.
Because, $$\|\mathbf{v}\|=\sqrt{|v_{1}^2+v_{2}^2+v_{3}^2+\cdots+v_{n}^2}.$$
(b) False.
Because, $$\mathbf{u} \cdot \mathbf{v}=u_{1} v_{1}+ u_{2} v_{2}+ u_{3} v_{3}+ \dots, u_{n} v_{n}.$$
