# Pre-Calculus 12: Matrices & Matrix Applications

## Video Lectures

Displaying all 33 video lectures.
 Lecture 1 Play Video What is a Matrix? 1In this video I will define what is a matrix and its rows and columns. Next video in the Matrices series can be seen at: http://youtu.be/YTV7ei1hyJI Lecture 2 Play Video What is a Matrix? 2In this video I will explain the matrix elements and its i, j (row, column) subscripts, mxn matrix. Next video in the Matrices series can be seen at: http://youtu.be/AaMIgwKtShQ Lecture 3 Play Video Row Echelon FormIn this video I will explain and show an example of a row-echelon form matrix. Next video in the Matrices series can be seen at: http://youtu.be/uDNeLykDJas Lecture 4 Play Video Reduced Row Echelon FormIn this video I will show how to reduce a row echelon form matrix. Next video in the Matrices series can be seen at: http://youtu.be/ElFIbVBZe8k Lecture 5 Play Video Method of Gaussian Elimination: ExampleIn this video I will use the method of Gaussian elimination to solve for the unknowns. Next video in the Matrices series can be seen at: http://youtu.be/5mD_CnbC7Zk Lecture 6 Play Video Method of Gaussian Elimination: 2x2 MatrixIn this video I will use the method of Gaussian elimination to solve for a 2x2 matrix. Next video in the Matrices series can be seen at: http://youtu.be/5EeqBabPSzg Lecture 7 Play Video Method of Gaussian Elimination: 3x3 Matrix*In this video I will use the method of Gaussian elimination to solve for a 3x3 matrix. Next video in the Matrices series can be seen at: http://youtu.be/ux2K_v63F0Y Lecture 8 Play Video Gaussian Elimination: 3x3 Matrix, No SolutionIn this video I will use the method of Gaussian elimination to solve for a system of 3 linear equations with no solution. Next video in the Matrices series can be seen at: http://youtu.be/aZgC7FnT9Ok Lecture 9 Play Video Gaussian Elimination: 3x3, Infinite SolutionsIn this video I will use the method of Gaussian elimination to solve for a system of 3 linear equations with infinite number of solutions. Next video in the Matrices series can be seen at: http://youtu.be/0D5z9WbdsBI Lecture 10 Play Video Gaussian Elimination: Example of Solving 3x3In this video I will use the method of Gaussian elimination to find x=? y=? z=? of a 3 equation 3 unknown system of equations. Next video in the Matrices series can be seen at: http://youtu.be/_numHGhNrZI Lecture 11 Play Video What are Equal Matrices?In this video I will explain what are equal matrices. Next video in the Matrices series can be seen at: http://youtu.be/sQ4od79mGRA Lecture 12 Play Video How to Add MatricesIn this video I will find the sum of 2 matrices. Next video in the Matrices series can be seen at: http://youtu.be/BLBG-9p3faw Lecture 13 Play Video How to Subtract MatricesIn this video I will find the difference of 2 matrices. Next video in the Matrices series can be seen at: http://youtu.be/DrR7z20PWEg Lecture 14 Play Video How to Multiply Matrices by a NumberIn this video I will find the scalar products with matrices. Find C=? if 4B=C where B and C are 2x2 matrices. Next video in the Matrices series can be seen at: http://youtu.be/6NVZBJGszjU Lecture 15 Play Video How to Solve Mixed Operations on MatricesIn this video I will find A-2B=? where A and B are matrices, mixed operations with matrices. Next video in the Matrices series can be seen at: http://youtu.be/NTk1GcYqzUc Lecture 16 Play Video How to Multiply (Square) MatricesIn this video I will explain the condition needed for square matrices multiplication. Next video in the Matrices series can be seen at: http://youtu.be/Sxyde1xtkpU Lecture 17 Play Video How to Multiply (Different Size) MatricesIn this video I will explain the condition needed for 2 matrices (of different sizes) multiplication. Next video in the Matrices series can be seen at: http://youtu.be/fQp_X2JGbp0 Lecture 18 Play Video Matrices that CANNOT be Multiplied TogetherIn this video I will explain why 2 matrices (3x1 and 2x3) cannot be multiplied together. Next video in the Matrices series can be seen at: http://youtu.be/iAZa-ysy_uQ Lecture 19 Play Video What is an Identity Matrix?In this video I will define, explain, and find the identity matrices to 1x1, 2x2, and 3x3 matrices. Next video in the Matrices series can be seen at: http://youtu.be/KoKWMSABkuM Lecture 20 Play Video What is the Inverse of a Matrix?In this video I will define and find the inverse of a 2x2 matrix. Next video in the Matrices series can be seen at: http://youtu.be/F_fyoVXaowY Lecture 21 Play Video Using the Determinant to Find the InverseIn this video I will find the inverse of a 2x2 matrix using a determinant, method 1. Next video in the Matrices series can be seen at: http://youtu.be/fPHPUDOEn-Q Lecture 22 Play Video Using Gaussian Elimin. to Find the InverseIn this video I will find the inverse of a 2x2 matrix using a the Gaussian elimination method. Next video in the Matrices series can be seen at: http://youtu.be/SfZa9Y0ZTfQ Lecture 23 Play Video Finding the Inverse of a 3x3 MatrixIn this video I will find the inverse of a 3x3 matrix using a the Gaussian elimination method. Next video in the Matrices series can be seen at: http://youtu.be/WKmPLI-y1wc Lecture 24 Play Video Dividing One Matrix by Another MatrixIn this video I will find the division of one matrix by another matrix. Next video in the Matrices series can be seen at: http://youtu.be/X8AG-gkifeU Lecture 25 Play Video Solving Sys of Linear Eqn with InverseIn this video I will explain how to find x=? y=? of systems of 2 linear equations using inverse matrices. Next video in the Matrices series can be seen at: http://youtu.be/kQjTb6qtim0 Lecture 26 Play Video Solving Sys of Linear Eqn with InverseIn this video I will find x=? y=? of systems of 2 linear equations using inverse matrices. Next video in the Matrices series can be seen at: http://youtu.be/yJ-vSmO-Ogg Lecture 27 Play Video Solving Sys of Linear Eqn with InverseIn this video I will find x=? y=? of 2 systems of 2 linear equations using determinants. Next video in the Matrices series can be seen at: http://youtu.be/wKUOJ8DjeLw Lecture 28 Play Video Solving Sys of Linear Eqn with InverseIn this video I will find x=? y=? of systems of 3 linear equations using inverse matrices. Next video in the Matrices series can be seen at: http://youtu.be/ZmQoZAh19-c Lecture 29 Play Video Find the Determinant of a 2x2 MatrixIn this video I will find the determinant of a 2x2 matrix. Next video in the Matrices series can be seen at: http://youtu.be/6MWu4BPR4Qs Lecture 30 Play Video Find the Determinant of a 3x3 Matrix 1In this video I will find the determinant of a 3x3 matrix by breaking a 3x3 matrix into 3-2x2 matrices. Next video in the Matrices series can be seen at: http://youtu.be/WsoPIeJj4X4 Lecture 31 Play Video Find the Determinant of a 3x3 Matrix 2In this video I will find the determinant of a 3x3 matrix by using the “diagonal” method. Next video in the Matrices series can be seen at: http://youtu.be/JMjuaMY5BsQ Lecture 32 Play Video Using Cramer's Rule to Find x=? y=?In this video I will find x=? y=? of systems of 2 linear equations using Cramer's rule. Next video in the Matrices series can be seen at: http://youtu.be/UfwXTMygeVs Lecture 33 Play Video Using Cramer's Rule to Find x=? y=? z=?In this video I will find x=? y=? z=? of systems of 3 linear equations using Cramer's rule. First video in the Matrices series can be seen at: https://youtu.be/pSgaeGFyLH0