Methematics

This is a testinAdvanced matrices and three-dimensional geometry — the algebra of linear systems and the geometry of lines and planes in space, worked the way exams and applications actually use them. ...

Enrolment key needed

This course is open to anyone with the key. Enter it once and this browser stays enrolled.

9 lessons · 26 min of reading

Matrices

From matrix algebra and determinants to rank, inverses, and the eigenvalue theory that ties them together.

4 lessons
  1. 🔒

    Matrix algebra and special matrices

    The operations, the algebra they obey, and the named matrices whose structure does the heavy lifting.

    Intermediate 3 min read
  2. 🔒

    Determinants and their properties

    One number that decides invertibility, scales volume, and turns long computations into short ones when you use its properties.

    Intermediate 3 min read
  3. 🔒

    The inverse of a matrix

    When it exists, two ways to compute it, and why the adjoint method is a proof, not a procedure.

    Advanced 3 min read
  4. 🔒

    Rank and solving linear systems

    One integer measures how much information a matrix really carries — and decides whether a system has no solution, one, or infinitely many.

    Advanced 3 min read

Three Dimensional Geometry

Directions, lines and planes in space — the vector machinery that turns spatial questions into short algebra.

5 lessons
  1. 🔒

    Direction cosines and direction ratios

    How a direction in space is encoded as three numbers, and the one identity that constrains them.

    Intermediate 3 min read
  2. 🔒

    The straight line in space

    A point and a direction fix a line — written as a vector equation, as symmetric Cartesian form, and as parametric coordinates.

    Intermediate 2 min read
  3. 🔒

    The plane

    A point and a normal fix a plane — and the normal vector, read straight from the equation, answers almost every question about it.

    Advanced 3 min read
  4. 🔒

    Angles, distances and the line–plane relationship

    Every angle and every intersection reduces to a dot product between the right two vectors — once you pick the right two.

    Advanced 3 min read
  5. 🔒

    Skew lines, shortest distance and coplanarity

    In space, two lines usually neither meet nor run parallel — and one scalar triple product settles the distance between them.

    Advanced 3 min read