Question

Take a look at the expression below here:
\[\begin{pmatrix}a\\b\end{pmatrix}\]
How can we tell if it is 2 × 1 matrix or notation of a binomial coefficient?

Answer 1

In general, you'll know by the context of the material you're reading. However, if that's not enough, matrices are usually denoted with square brackets, unless it's a vector. Again, going by convention, vectors will usually have their elements labeled with subscripts (or superscripts) rather than different letters. So, I would guess that notation there would be for a binomial coefficient, if given no context to suggest otherwise.

Answer 2

I see. Thanks.

Answer 3

You're welcome.

Notation relies heavily on context, the same way language does. For example, the word ash has two meanings.