I have an Excel spreadsheet with the following formula (paraphrased):
=MMULT( MMULT(vector_as_n_column_matrix, n_by_n_square_matrix) ,TRANSPOSE(vector_as_n_column_matrix) )
the matrix and vector contain floating point values. Excel evaluates this formula as a scalar. I don't recall matrix math working that way. However, it's been over 30 years since I studies linear algebra.
Does it make sense that the result should be a scalar? Can you explain why in terms of linear algebra?