Solution
= Solution
<Vector addition>[Adding the vectors] component by component gives
$$
\mathbf u+\mathbf v=(5a,0,2a)^T=\mathbf0.
$$
Consequently $\boxed{a=0}$. The requirement that the <vectors> be nonzero then implies $b\ne0$.
= Solution
<Vector addition>[Adding the vectors] component by component gives
$$
\mathbf u+\mathbf v=(5a,0,2a)^T=\mathbf0.
$$
Consequently $\boxed{a=0}$. The requirement that the <vectors> be nonzero then implies $b\ne0$.