Update doc/specs/stdlib_math.md

Co-authored-by: Jeremie Vandenplas <jeremie.vandenplas@gmail.com>

Author: igirault

doc/specs/stdlib_math.md

@@ -561,7 +561,7 @@ When both `prepend` and `append` are not present, the result `y` has one fewer e
 
 Computes a list of coordinate matrices from coordinate vectors.
 
-For $n \geq 1$ coordinate vectors $(x_1, x_2, ..., x_n)$ of sizes $(s_1, s_2, ..., s_n)$, `meshgrid` computes $N$ coordinate matrices $(X_1, X_2, ..., X_n)$ with identical shape corresponding to the selected indexing:
+For $n \geq 1$ coordinate vectors $(x_1, x_2, ..., x_n)$ of sizes $(s_1, s_2, ..., s_n)$, `meshgrid` computes $n$ coordinate matrices $(X_1, X_2, ..., X_n)$ with identical shape corresponding to the selected indexing:
 - Cartesian indexing (default behavior): the shape of the coordinate matrices is $(s_2, s_1, s_3, s_4, ... s_n)$.
 - matrix indexing: the shape of the coordinate matrices is $(s_1, s_2, s_3, s_4, ... s_n)$.