Problem Statement

Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length.

As an example, compute the dot product of the vectors:

If implementing the dot product of two vectors directly:

Let's start with the solution:

[[\1-$0=~][$d;2*1+\-ø\$d;2+\-ø@*@+]#]p:
3d: {Vectors' length}
1 3 5_ 4 2_ 1_ d;$1+ø@*p;!%. {Output: 3}