Introduction to Linear Algebra, Gilbert Strang, 2023 (Wellesley-Cambridge Press) - A foundational textbook that clearly introduces vector operations, including scalar multiplication, its algebraic definition, and geometric interpretation. (5th edition)
Linear Algebra and Its Applications, David C. Lay, Steven R. Lay, and Judi J. McDonald, 2020 (Pearson) - A widely used textbook providing a clear explanation of basic vector operations like scalar multiplication, often with practical examples. (6th edition)
User guide: The N-dimensional array (ndarray), NumPy Developers, 2024 - Official NumPy documentation detailing how arithmetic operations, including scalar multiplication, are performed on ndarray objects.