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Three examples of determinant of 2x2 matrices.

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\n

The determinant of a 2 x 2 matrix

\n

\\[A = \\begin{pmatrix} a_{11} \\ a_{12} \\\\ a_{21} \\ a_{22}    \\end{pmatrix}\\]

\n

is given by

\n

\\[det(A)  = a_{11}a_{22} - a_{21}a_{12} \\]

\n

For each of the cases above:

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a) 

\n

\\[det(A) = (\\var{a[0][0]}\\times\\var{a[1][1]}) - (\\var{a[1][0]}\\times\\var{a[0][1]}) = \\simplify{{a[0][0]}*{a[1][1]} - {a[1][0]}*{a[0][1]}}  \\]

\n

\n

b)

\n

\\[det(B) = (\\var{b[0][0]}\\times\\var{b[1][1]}) - (\\var{b[1][0]}\\times\\var{b[0][1]}) = \\simplify{{b[0][0]}*{b[1][1]} - {b[1][0]}*{b[0][1]}}  \\]

\n

c)

\n

\\[det(C) = (\\var{c[0][0]}\\times\\var{c[1][1]}) - (\\var{c[1][0]}\\times\\var{c[0][1]}) = \\simplify{{c[0][0]}*{c[1][1]} - {c[1][0]}*{c[0][1]}}  \\]

\n

For further information see Section 4 of the Chapter 10 Notes. 

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Let 
\\[A=\\simplify{{a}},\\;\\; B=\\simplify{{b}},\\;\\; C=\\simplify{{c}}\\]
Calculate the determinants of these matrices

\n

 

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$det(C) = $ [[0]]

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