Matrices: watch it solved step by step

Determinant, inverse, transpose, products and eigenvalues of 2×2 and 3×3 matrices, with a check. Level: A-level / University. Type any problem of this kind and the Lab works it out and animates every move, with a plain-words explanation of why.

Worked example: [[1, 2], [3, 4]] * [[0, 1], [1, 0]]

  1. The matrices. To multiply matrices, each entry of the answer is a row of A times a column of B: multiply along, add up.
  2. Row 1 times each column. Take the first row of A and pair it with each column of B.
  3. The other rows. Repeat for every row of A.
  4. The product. Put the entries together.
  5. Is it the same the other way round?. Matrix multiplication is not commutative: AB and BA are usually different.

Answer: AB = [2, 1], [4, 3]

Practise matrices with problems the Lab marks for you.

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