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Khan Academy
Khan Academy: Orthogonal Projections: Projection Is Closest Vector in Subspace
A video lesson proving that the projection of a vector is actually the closest vector in the subspace to the original vector.
Khan Academy
Khan Academy: A Projection Onto a Subspace Is a Linear Transforma
A video lesson proving that any projection onto a subspace is actually a linear transformation. It includes a brief description of how the results can be useful in 3-D graphical programming.
Khan Academy
Khan Academy: Orthogonal Projections: Least Squares Approximation
A video lesson explaining the least squares approximation for otherwise unsolvable matrix equations. Presents the motivation for why the least squares approximation is useful. Derives the formula for finding the least squares approximation.
Khan Academy
Khan Academy: Orthogonal Projections: Another Least Squares Example
This is a video lesson on using the least squares approximation to find the line of best fit for a set of points. Includes a concrete example dealing with a set of 4 points.
Khan Academy
Khan Academy: Orthogonal Projections: Subspace Projection Matrix Example
This video uses a concrete example for how to find the projection of an arbitrary vector onto a specific subspace in R4. Uses a 4 x 2 basis matrix for the subspace.
Khan Academy
Khan Academy: Orthogonal Projections: Visualizing a Projection Onto a Plane
A video lesson showing what a projection onto a plane could look like. Illustrates that the newly derived definition of a projection holds true for projections onto subspaces other than lines.
Khan Academy
Khan Academy: Orthogonal Projections: Another Example of a Projection Matrix
A video lesson figuring out the transformation matrix for a projection onto a subspace by figuring out the matrix for the projection onto the subspace's orthogonal complement first.