Builds on algebra
Linear algebra
Understand vectors, matrices, and the geometry behind data and its transformations.
Inside this subject
Read at your own pace01Vectors8 lessons
- 01Vector coordinates
Interpret the entries of a vector in a named coordinate system.
- 02Vector addition
Add two vectors of the same dimension.
- 03Scalar multiplication
Scale each coordinate of a vector by a scalar.
- 04Vector differences
Compute the displacement between two coordinate vectors.
- 05Linear combinations
Construct a weighted sum of supplied vectors.
- 06Dot products
Compute the dot product of two equal-length vectors.
- 07Euclidean length
Compute the Euclidean length of a vector.
- 08Unit vectors
Normalize a nonzero vector to unit length.
02Vector geometry5 lessons
- 01Euclidean distance
Compute the Euclidean distance between two vectors.
- 02Orthogonal vectors
Decide whether two vectors are orthogonal using their dot product.
- 03Cosine similarity
Compute directional similarity for two nonzero vectors.
- 04Embedding similarity
Interpret a supplied embedding ranking within its stated representation.
- 05L1 norm
Compute the L1 norm of a vector.
03Matrices as operations6 lessons
- 01Matrix shape
Identify the row and column dimensions of a matrix.
- 02Matrix entries
Retrieve a matrix entry using its row and column indices.
- 03Matrix addition
Add matrices of equal shape.
- 04Matrix scaling
Multiply each matrix entry by a scalar.
- 05Matrix-vector products
Compute a matrix-vector product from row dot products.
- 06Column combinations
Express a matrix-vector product as a combination of its columns.
04Matrix products4 lessons
05Eliminating variables6 lessons
- 01Systems as matrices
Encode a finite linear system as Ax=b.
- 02Row operations
Apply one solution-preserving elementary row operation.
- 03Gaussian elimination
Eliminate a variable using elementary row operations.
- 04Pivots
Identify pivot positions in row-echelon form.
- 05Back substitution
Solve a triangular system by back substitution.
- 06Reduced echelon form
Reduce an echelon matrix to reduced row-echelon form.
06Solutions and inverses3 lessons
07Span and basis5 lessons
- 01Span
Decide whether a vector lies in the span of supplied vectors.
- 02Subspaces
Check the defining closure conditions for a candidate real subspace.
- 03Linear independence
Test whether a supplied vector list is linearly independent.
- 04Bases
Verify a basis for a specified finite-dimensional subspace.
- 05Dimension
Determine subspace dimension from a basis.
08Matrix subspaces2 lessons
09Linear maps3 lessons
10Projections and least squares6 lessons
- 01Projection onto a line
Compute the orthogonal projection onto a nonzero vector's span.
- 02Orthonormal bases
Verify that a supplied basis is orthonormal.
- 03Projection onto a subspace
Project a vector using a supplied orthonormal basis.
- 04Least-squares geometry
Identify the closest attainable output in an inconsistent linear system.
- 05QR factorization
Use supplied reduced QR factors to solve a full-column-rank least-squares problem.
- 06Normal equations
Form the normal equations for a linear least-squares problem.
11Low-rank approximation6 lessons
- 01Singular value decomposition
Interpret the three transformations in a supplied SVD.
- 02Singular values
Infer rank from the nonzero singular values of a matrix.
- 03Truncated SVD
Construct a rank-k approximation from supplied singular components.
- 04Frobenius norm
Compute a matrix's Frobenius norm.
- 05Approximation error
Compute truncated-SVD Frobenius error from discarded singular values.
- 06Condition numbers
Interpret the ratio of largest to smallest nonzero singular values for a full-rank square system.