Weird vector notation $\vec{v}=[1 \ 2 \ 3]^T$

Question

In a famous Engineering course in Brazil all of the vector (Analytic Geometry) material is written in the following fashion:

$$\vec{v}=[1 \ 2 \ 3]^T$$

represents what is commonly written as

$$\vec{v} = (1,2,3)$$

Is that notation from somewhere specific (a book, a country...)? Is it wrong?

Thank you.

Answer 1

Both are acceptable. The first example, $\vec{v}=[1 \ 2 \ 3]^T$, is the transpose of a row vector, or equivalently, a column vector. The second example, $\vec{v} = (1,2,3)$, uses ordered set notation instead of matrix notation, but lists each component just the same.