## Is this a Norm?

How is the following formula calculated, assuming $a$ and $b$ are $n$-dimensional vectors? $\parallel \overrightarrow{a} – \overrightarrow{b}\parallel^2$ Answer as $(\vec{a}-\vec{b}).(\vec{a}-\vec{b})$ AttributionSource : Link , Question Author : Scholle , Answer Author : John McGee