Laplace's expansion of a determinant is also called
A
Cofactor expansion
B
Transpose expansion
C
Matrix inversion
D
Row reduction
Analysis & Theory
Laplace’s expansion is also known as cofactor expansion.
Laplace expansion can be performed along
A
Only first row
B
Only last row
C
Any row or any column
D
Only diagonal
Analysis & Theory
Determinant can be expanded along any row or any column.
If a determinant of order n is expanded using Laplace expansion, then it breaks into
A
n determinants of order (n−1)
B
n^2 determinants of order (n−1)
C
One determinant of same order
D
Always zero
Analysis & Theory
Expansion along a row/column gives sum of n cofactors, each involving determinant of order (n−1).
Cofactor of element aᵢⱼ is defined as
A
Minor of aᵢⱼ
B
(-1)^(i+j) × Minor of aᵢⱼ
C
Transpose of element
D
Inverse of minor
Analysis & Theory
Cofactor = (−1)^(i+j) × Minor of aᵢⱼ.
Laplace expansion of determinant along first row is
A
a₁₁C₁₁ + a₁₂C₁₂ + … + a₁nC₁n
B
a₁₁ + a₁₂ + … + a₁n
C
Sum of all minors only
D
Product of all cofactors
Analysis & Theory
Formula: det(A) = Σ a₁ⱼ × C₁ⱼ (sum of element × cofactor).
Laplace expansion is useful for
A
Adding matrices
B
Computing determinant
C
Finding transpose
D
Matrix multiplication
Analysis & Theory
Laplace expansion is a systematic method to compute determinants of higher order.
In Laplace expansion, if a row has many zero elements, it is advantageous to expand along that row because
A
Determinant becomes zero
B
Calculation simplifies
C
Transpose is obtained
D
Inverse is obtained
Analysis & Theory
Zeros reduce number of cofactors to calculate, simplifying computation.
Laplace expansion of 2×2 determinant [[a, b], [c, d]] along first row gives
A
ad − bc
B
ab + cd
C
a+b+c+d
D
abcd
Analysis & Theory
Expanding: det = a·d − b·c.
The sign factor (−1)^(i+j) in Laplace expansion ensures
A
Determinant symmetry
B
Correct orientation of minors
C
All cofactors positive
D
Zero determinant
Analysis & Theory
The alternating sign factor (−1)^(i+j) is essential to define cofactors correctly.
Laplace expansion along different rows or columns gives
A
Different values of determinant
B
Same value of determinant
C
Zero always
D
Inverse matrix
Analysis & Theory
Determinant value is independent of choice of row/column for expansion.