WildLinAlg8: Inverting 3x3 matrices

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WildLinAlg: A first course in Linear Algebra

Education


This is the 8th lecture in this series on Linear Algebra. Here we solve the most fundamental problem in the subject in the 3x3 case---in such a way that extension to higher dimensions becomes almost obvious. What is the fundamental problem? It is: How to invert a change of coordinates? Or in matrix terms: How to find the inverse of a matrix? And the answer rests squarely on the wonderful function called the determinant. Be prepared for some algebra, but it is beautiful algebra!