Dividing vectors directly in dot products is not valid, as dot products yield scalar values, not vectors. In the example provided, a dot b results in a numerical value, specifically 11 for vectors a = (1,2) and b = (3,4). The discussion clarifies that dividing the results of dot products, such as a . a / b . a, does not equate to dividing the vectors themselves. Instead, it suggests that the outcome is a scalar division rather than a vector operation. Understanding the distinction between vector operations and scalar results is crucial for accurate calculations in vector mathematics.