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Example Questions
Example Question #19 : Range And Null Space Of A Matrix
, the set of all continuous real-valued functions defined on
, is a vector space under the usual rules of addition and scalar multiplication.
Let be the set of all functions of the form
for some real
True or false: is a subspace of
.
True
False
True
A set is a subspace of a vector space if and only if two conditions hold, both of which are tested here.
The first condition is closure under addition - that is:
If , then
Let as defined. Then for some
,
and
Then
or
or
. The first condition is met.
The second condition is closure under scalar multiplication - that is:
If and
is a scalar, then
Let as defined. Then for some
,
For any scalar ,
or
. The second condition is met.
, as defined, is a subspace.
Example Question #12 : Range And Null Space Of A Matrix
If is an
matrix, find
Since a basis for the row space and the column space of a matrix have the same, number of vectors then their dimensions are the same, say .
By the rank-nullity theorem, we have , or same to say
.
.
Hence .
Finally, applying the rank-nullity theorem to the transpose of , we have
, or the same to say
.
(The row space dimension of
is the same as its transpose.)
.
Adding all four of our findings together gives us
.
Example Question #1 : The Determinant
Calculate the determinant of matrix A where
45
0
Not Possible
10
-50
Not Possible
The matrix must be square to calculate its determinant, therefore, it is not possible to calculate the determinant for this matrix.
Example Question #2 : The Determinant
Calculate the determinant of matrix A where,
7
17
12
-7
0
7
To calculate the determinant of a 2x2 matrix, we can use the equation
Example Question #3 : The Determinant
Calculate the determinant of matrix A where,
-315
504
0
54
-504
504
To calculate the determinant of a 2x2 matrix, we can use the equation
Example Question #4 : The Determinant
Calculate the determinant of matrix A where,
0
17
-15
16
15
16
To calculate the determinant of a 2x2 matrix, we can use the equation
Example Question #5 : The Determinant
Calculate the determinant of matrix A where,
0
26
-24
15
-26
-26
Calculating the determinant of a 3x3 matrix is more difficult than a 2x2 matrix. To calculate the determinant of a 3x3 matrix, we use the following
Example Question #6 : The Determinant
Calculate the determinant of matrix A where,
50
49
-49
-50
0
-50
Calculating the determinant of a 3x3 matrix is more difficult than a 2x2 matrix. To calculate the determinant of a 3x3 matrix, we use the following
Example Question #7 : The Determinant
Calculate the determinant of .
By definition,
,
therefore,
.
Example Question #1 : The Determinant
Calculate the determinant of
For simplicity, we will find the determinant by expanding along the second row. Consider the following:
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