Solution
= Solution
The <dot product> is $\boldsymbol a\cdot\boldsymbol b=2-1+2=3$, and both <vectors> have length $\sqrt6$. The <angle between vectors> therefore satisfies $\cos\theta=3/6=1/2$, giving
$$
\boxed{\theta=\pi/3.}
$$
= Solution
The <dot product> is $\boldsymbol a\cdot\boldsymbol b=2-1+2=3$, and both <vectors> have length $\sqrt6$. The <angle between vectors> therefore satisfies $\cos\theta=3/6=1/2$, giving
$$
\boxed{\theta=\pi/3.}
$$