Find Inverse Triangular Matrix (3x3) (Level 1)

This math topic focuses on finding the inverse of 3x3 triangular matrices. It contains several problems where students are asked to determine the inverse of a given triangular matrix, if it exists. Each problem presents a matrix and multiple choice answers, depicting various potential inverses of the matrix. Students are expected to apply their understanding of matrix operations, specifically focusing on the computation of the inverse of lower and upper triangular matrices.

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Find Inverse Triangular Matrix (3x3)

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Find the inverse of this matrix if it has one

[942084005]\left[ {\begin{array} {ccc} 9 & 4 & 2 \\ 0 & 8 & 4 \\ 0 & 0 & 5 \end{array} } \right]

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Matrices - Find Inverse Triangular Matrix (3x3) Worksheet

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Math worksheet on 'Matrices - Find Inverse Triangular Matrix (3x3) (Level 1)'. Part of a broader unit on 'Matrices' Learn online: app.mobius.academy/math/units/matrices/
1
Find the inverse of this matrix if it has one
A LaTex expression showing \left[ {\begin{array} {ccc} 8 & 5 & 6 \\ 0 & 3 & 2 \\ 0 & 0 & 3 \end{array} } \right]
a A LaTex expression showing \left[ {\begin{array} {ccc} -0.19 & 0.31 & 0.17 \\ 0 & -0.5 & 0.33 \\ 0 & 0 & -0.5 \end{array} } \right]
b A LaTex expression showing \left[ {\begin{array} {ccc} 0.11 & 0.07 & 0.08 \\ 0 & 0.04 & 0.03 \\ 0 & 0 & 0.04 \end{array} } \right]
c A LaTex expression showing \left[ {\begin{array} {ccc} 3 & 9 & 8 \\ 1 & 4 & 4 \\ 2 & 0 & 4 \end{array} } \right]
d A LaTex expression showing \left[ {\begin{array} {ccc} 0.12 & -0.21 & -0.11 \\ 0 & 0.33 & -0.22 \\ 0 & 0 & 0.33 \end{array} } \right]
e A LaTex expression showing \left[ {\begin{array} {ccc} 0.12 & -0.21 & -0.11 \\ 0 & 0.33 & -2.22 \\ 0 & 0 & 0.33 \end{array} } \right]
f A LaTex expression showing \left[ {\begin{array} {ccc} 0.1 & 0.06 & 0.08 \\ 0 & 0.04 & 0.03 \\ 0 & 0 & 0.04 \end{array} } \right]
2
Find the inverse of this matrix if it has one
A LaTex expression showing \left[ {\begin{array} {ccc} 3 & 0 & 0 \\ 8 & 5 & 0 \\ 2 & 5 & 2 \end{array} } \right]
a A LaTex expression showing \left[ {\begin{array} {ccc} 0.12 & 0 & 0 \\ 0.32 & 0.2 & 0 \\ 0.08 & 0.2 & 0.08 \end{array} } \right]
b A LaTex expression showing \left[ {\begin{array} {ccc} 0.33 & 0 & 0 \\ -0.53 & 0.2 & 0 \\ 1 & -0.5 & 0.5 \end{array} } \right]
c A LaTex expression showing \left[ {\begin{array} {ccc} 90 & 0 & 0 \\ 240 & 150 & 0 \\ 60 & 150 & 60 \end{array} } \right]
d A LaTex expression showing \left[ {\begin{array} {ccc} -0.17 & 0 & 0 \\ 0.27 & -0.1 & 0 \\ -0.5 & 0.25 & -0.25 \end{array} } \right]
e A LaTex expression showing \left[ {\begin{array} {ccc} 0.25 & 0 & 0 \\ -0.4 & 0.15 & 0 \\ 0.75 & -0.38 & 0.38 \end{array} } \right]
f A LaTex expression showing \left[ {\begin{array} {ccc} -0.5 & 0 & 0 \\ 0.8 & -0.3 & 0 \\ -1.5 & 0.75 & -0.75 \end{array} } \right]
3
Find the inverse of this matrix if it has one
A LaTex expression showing \left[ {\begin{array} {ccc} 4 & 5 & 4 \\ 0 & 4 & 5 \\ 0 & 0 & 8 \end{array} } \right]
a A LaTex expression showing \left[ {\begin{array} {ccc} 0.03 & 0.04 & 0.03 \\ 0 & 0.03 & 0.04 \\ 0 & 0 & 0.07 \end{array} } \right]
b A LaTex expression showing \left[ {\begin{array} {ccc} 0 & 9 & 1 \\ 8 & 4 & 5 \\ 9 & 8 & 3 \end{array} } \right]
c A LaTex expression showing \left[ {\begin{array} {ccc} -0.19 & 0.23 & -0.05 \\ 0 & -0.19 & 0.12 \\ 0 & 0 & -0.09 \end{array} } \right]
d A LaTex expression showing \left[ {\begin{array} {ccc} 0.25 & -0.31 & 0.07 \\ 0 & 0.25 & -0.16 \\ 0 & 0 & 0.12 \end{array} } \right]
e A LaTex expression showing \left[ {\begin{array} {ccc} 0.03 & 0.04 & 0.03 \\ 0 & 0.03 & 0.04 \\ 0 & 0 & 0.06 \end{array} } \right]
f A LaTex expression showing \left[ {\begin{array} {ccc} 0.06 & -0.08 & 0.02 \\ 0 & 0.06 & -0.04 \\ 0 & 0 & 0.03 \end{array} } \right]
4
Find the inverse of this matrix if it has one
A LaTex expression showing \left[ {\begin{array} {ccc} 7 & 4 & 7 \\ 0 & 3 & 1 \\ 0 & 0 & 9 \end{array} } \right]
a A LaTex expression showing \left[ {\begin{array} {ccc} 0.03 & 0.02 & 0.03 \\ 0 & 0.01 & 0 \\ 0 & 0 & 0.04 \end{array} } \right]
b A LaTex expression showing \left[ {\begin{array} {ccc} 3 & 8 & 3 \\ 9 & 7 & 3 \\ 0 & 9 & 3 \end{array} } \right]
c A LaTex expression showing \left[ {\begin{array} {ccc} 0.14 & -0.19 & -0.09 \\ 0 & 0.33 & -0.04 \\ 0 & 0 & 0.11 \end{array} } \right]
d A LaTex expression showing \left[ {\begin{array} {ccc} 0.14 & -0.19 & 0.91 \\ -1 & 0.33 & 0.96 \\ 0 & -2 & 0.11 \end{array} } \right]
e A LaTex expression showing \left[ {\begin{array} {ccc} 0 & 5 & 3 \\ 4 & 0 & 4 \\ 8 & 2 & 3 \end{array} } \right]
f A LaTex expression showing \left[ {\begin{array} {ccc} 0.04 & 0.02 & 0.04 \\ 0 & 0.02 & 0.01 \\ 0 & 0 & 0.05 \end{array} } \right]
5
Find the inverse of this matrix if it has one
A LaTex expression showing \left[ {\begin{array} {ccc} 9 & 4 & 2 \\ 0 & 8 & 4 \\ 0 & 0 & 5 \end{array} } \right]
a A LaTex expression showing \left[ {\begin{array} {ccc} 0.17 & -0.08 & 0 \\ 0 & 0.19 & -0.15 \\ 0 & 0 & 0.3 \end{array} } \right]
b A LaTex expression showing \left[ {\begin{array} {ccc} 0.06 & -0.03 & 0 \\ 0 & 0.06 & -0.05 \\ 0 & 0 & 0.1 \end{array} } \right]
c A LaTex expression showing \left[ {\begin{array} {ccc} 0.19 & -0.1 & 0 \\ 0 & 0.22 & -0.18 \\ 0 & 0 & 0.35 \end{array} } \right]
d A LaTex expression showing \left[ {\begin{array} {ccc} 0.03 & 0.01 & 0.01 \\ 0 & 0.02 & 0.01 \\ 0 & 0 & 0.01 \end{array} } \right]
e A LaTex expression showing undefined
f A LaTex expression showing \left[ {\begin{array} {ccc} 0.11 & -0.06 & 0 \\ 0 & 0.12 & -0.1 \\ 0 & 0 & 0.2 \end{array} } \right]
6
Find the inverse of this matrix if it has one
A LaTex expression showing \left[ {\begin{array} {ccc} 6 & 8 & 7 \\ 0 & 7 & 1 \\ 0 & 0 & 6 \end{array} } \right]
a A LaTex expression showing \left[ {\begin{array} {ccc} 0.33 & -0.38 & -0.33 \\ 0 & 0.29 & -0.05 \\ 0 & 0 & 0.33 \end{array} } \right]
b A LaTex expression showing undefined
c A LaTex expression showing \left[ {\begin{array} {ccc} 0.02 & 0.03 & 0.03 \\ 0 & 0.03 & 0 \\ 0 & 0 & 0.02 \end{array} } \right]
d A LaTex expression showing \left[ {\begin{array} {ccc} 1,512 & 2,016 & 1,764 \\ 0 & 1,764 & 252 \\ 0 & 0 & 1,512 \end{array} } \right]
e A LaTex expression showing \left[ {\begin{array} {ccc} 0.17 & -0.19 & -0.16 \\ 0 & 0.14 & -0.02 \\ 0 & 0 & 0.17 \end{array} } \right]
f A LaTex expression showing \left[ {\begin{array} {ccc} 8 & 9 & 1 \\ 7 & 5 & 9 \\ 2 & 3 & 9 \end{array} } \right]
7
Find the inverse of this matrix if it has one
A LaTex expression showing \left[ {\begin{array} {ccc} 6 & 3 & 2 \\ 0 & 6 & 8 \\ 0 & 0 & 1 \end{array} } \right]
a A LaTex expression showing \left[ {\begin{array} {ccc} -0.33 & 0.17 & -0.67 \\ 0 & -0.33 & 2.67 \\ 0 & 0 & -2 \end{array} } \right]
b A LaTex expression showing undefined
c A LaTex expression showing \left[ {\begin{array} {ccc} 0.17 & -0.08 & 0.33 \\ 0 & 0.17 & -1.33 \\ 0 & 0 & 1 \end{array} } \right]
d A LaTex expression showing \left[ {\begin{array} {ccc} 7 & 6 & 7 \\ 2 & 1 & 8 \\ 4 & 5 & 2 \end{array} } \right]
e A LaTex expression showing \left[ {\begin{array} {ccc} -0.08 & 0.04 & -0.17 \\ 0 & -0.08 & 0.67 \\ 0 & 0 & -0.5 \end{array} } \right]
f A LaTex expression showing \left[ {\begin{array} {ccc} -0.04 & 0.02 & -0.08 \\ 0 & -0.04 & 0.33 \\ 0 & 0 & -0.25 \end{array} } \right]