Determinants and Inverses flashcards
14 practice cards drawn from the Determinants and Inverses lessons. Tap a card to turn it over. Every answer is checked against the lesson it came from.
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What is the determinant of this matrix?
3
from “The Determinant of a 2 × 2 Matrix”
Does this matrix have an inverse?
no
from “The Determinant of a 2 × 2 Matrix”
This matrix has determinant 1. Which matrix is its inverse?
(2 −5; −1 3)
from “The Inverse of a 2 × 2 Matrix”
The determinant here is 2. What goes in row 1, column 1 of the inverse?
2
from “The Inverse of a 2 × 2 Matrix”
What is x?
1
from “Solving Simultaneous Equations with a Matrix Inverse”
This pair cannot be solved this way. What is det A?
0
from “Solving Simultaneous Equations with a Matrix Inverse”
Expanding along row 1, what sign goes with the entry in column 1?
plus
from “The Determinant of a 3 × 3 Matrix”
What is the determinant of the 2 × 2 left in gold?
-9
from “The Determinant of a 3 × 3 Matrix”
What sign does the cofactor in row 2, column 3 take?
minus
from “The Inverse of a 3 × 3 Matrix”
What is the cofactor of the entry in row 3, column 2?
-25
from “The Inverse of a 3 × 3 Matrix”
came out as this column. What is x?
1
from “Solving Three Equations with a Matrix Inverse”
Why can this system not be solved by an inverse?
det A is 0, so there is no inverse
from “Solving Three Equations with a Matrix Inverse”
det B is 0 because row 3 is row 1 plus row 2, and the totals add the same way. How do the planes meet?
along a whole line
from “The Geometry of Three Planes”
det B is 0 but the totals disagree. How do the three planes meet?
they do not meet at all
from “The Geometry of Three Planes”