All of its leading top-left sub-determinants (pivots) are positive. The quadratic form xTAxx to the cap T-th power cap A x is strictly positive for every non-zero vector Geometric View The graph of the quadratic energy function
For further study, watch his MIT OpenCourseWare lectures (18.06), work through the problem sets, and experiment with Python (NumPy) to see these concepts in action. lecture notes for linear algebra gilbert strang
ATAx̂=ATbcap A to the cap T-th power cap A x hat equals cap A to the cap T-th power b Solving for All of its leading top-left sub-determinants (pivots) are
Dot product, projections, Gram-Schmidt, QR factorization, least squares. watch his MIT OpenCourseWare lectures (18.06)
Visualizing matrix operations as shifts, rotations, and projections in space.
From these, you get: