CUET UG Applied Mathematics Booster Test 2 - Determinants and Their Properties
π Answers are locked once submitted β results and explanations appear at the end.
QUESTION 1 OF 20
If f(A) = k represents the determinant function mapping a matrix A to a number k, what strictly forms the domain (X) of this mapping function f?
QUESTION 2 OF 20
Match the specific matrices to their corresponding determinant values based on the square matrix association framework.
| List I | List II |
|---|---|
| 1. Matrix Row 1: (4) | a. 5 |
| 2. Matrix Row 1: (2, 5), Row 2: (-1, 0) | b. 4 |
| 3. Matrix Row 1: (1, 0), Row 2: (0, 1) | c. 1 |
| 4. Matrix Row 1: (2, 3) | d. Determinant not defined |
QUESTION 3 OF 20
If A is a 3 Γ 3 square matrix, which of the following logical statements hold true for computing its minors?
1. The minor of (a_{12}) involves evaluating a 2 Γ 2 determinant.
2. Minor (M_{31}) is computed by deleting the 3rd row and the 1st column.
3. The minor of an element is independent of the algebraic sign factor ((-1)^{i+j}).
4. A 2 Γ 3 matrix has perfectly defined minors for all elements.
QUESTION 4 OF 20
Identify the mathematically INCORRECT statement regarding minor evaluation:
QUESTION 5 OF 20
In a mixture problem tracking determinant values, if the minor M_23 evaluates to 13 for a specific matrix element, what is the precisely defined cofactor A_23?
QUESTION 6 OF 20
Under the strict constraint that an element's position yields an even sum of its row and column indices (i.e., i+j is an even integer), how does the cofactor A_ij compare algebraically to its minor M_ij?
QUESTION 7 OF 20
Calculate the equated determinant integer (EMI) for the order 2 matrix modeled by Row 1: (-9, 2) and Row 2: (1, -7).
**Correct Answer: A) (-9 * -7) - (2 * 1) = 61**
QUESTION 8 OF 20
In an order 3 matrix, if you calculate the moving average-like cross-sum: a11A31 + a12A32 + a13*A33, what is the resulting theoretical value?
QUESTION 9 OF 20
Given a square matrix A with a determinant |A| = 42, what is the probability-based certainty of the value of |A'| (the transpose of matrix A)?
QUESTION 10 OF 20
P10 VECTORS If vector row R1 is interchanged directly with vector row R3 in a matrix A (where initially |A| = 15), what is the newly formed determinant value?
QUESTION 11 OF 20
If a coordinate matrix yields a determinant area calculation of exactly 0 (indicating that the 3 points are structurally collinear), the matrix is mathematically defined as:
QUESTION 12 OF 20
For a matrix P to possess a valid inverse (P^-1), which integral condition must its determinant |P| firmly satisfy to be deemed non-singular?
QUESTION 13 OF 20
If the first and third columns of a 3x3 determinant are completely identical in every element, the final evaluated value of the determinant is:
QUESTION 14 OF 20
If a matrix represents a system where an entire row is composed exclusively of zeros, evaluating its determinant strictly categorizes the matrix as:
QUESTION 15 OF 20
If Row 1 elements are exactly proportional to Row 2 elements by a scalar factor k (e.g., R1 = k * R2), the determinant will evaluate to:
QUESTION 16 OF 20
If the linear operation C1 -> C1 + 5C2 is applied to a matrix bearing an initial determinant D, the new determinant will mathematically evaluate to:
QUESTION 17 OF 20
If a 3x3 matrix A has a determinant of 10, and a scalar multiple k=3 is multiplied into every single element of matrix A, what is the determinant of the newly formed matrix?
QUESTION 18 OF 20
Given two 2x2 square matrices A and B, if |A| = -2 and |B| = 6, what is the numerical value of the combined product determinant |AB|?
QUESTION 19 OF 20
If a single column in a 3x3 matrix is expressed as the sum of three algebraic terms, how many distinct determinants can the original determinant be split into?
QUESTION 20 OF 20
During matrix splitting via the summation property, what must logically happen to the rows or columns that do NOT contain the summed terms?
Test Complete!
Answer Review
1 If f(A) = k represents the determinant function mapping a matrix A to a number k, what strictly forms the domain (X) of this mapping function f?
οΏ½οΏ½ Determinants are defined only for square matrices. οΏ½οΏ½ Rectangular matrices do not possess determinants. οΏ½οΏ½ Hence the domain consists of all square matrices.
The determinant is a scalar value associated only with square matrices. If a matrix is not square, the determinant cannot be evaluated. Option C is correct because the determinant function maps every square matrix to a scalar value. Option A is incorrect because real numbers are outputs (codomain), not inputs. Option B is incorrect because rectangular matrices do not have determinants. Option D is incorrect because even singular matrices have determinants; their determinant is simply zero.
- οΏ½οΏ½ Option A β Real numbers represent determinant values, not the domain matrices.
- οΏ½οΏ½ Option B β Determinants are undefined for rectangular matrices.
- οΏ½οΏ½ Option D β Singular matrices are also square matrices and possess determinants equal to zero.
Used: Elimination
Application: Remove options involving non-square matrices or outputs instead of inputs.
Final Logic: Since determinants exist only for square matrices, the domain must be all square matrices.
"Determinant demands squares."
2 Match the specific matrices to their corresponding determinant values based on the square matrix association framework.
| List I | List II |
|---|---|
| 1. Matrix Row 1: (4) | a. 5 |
| 2. Matrix Row 1: (2, 5), Row 2: (-1, 0) | b. 4 |
| 3. Matrix Row 1: (1, 0), Row 2: (0, 1) | c. 1 |
| 4. Matrix Row 1: (2, 3) | d. Determinant not defined |
οΏ½οΏ½ A 1Γ1 determinant equals its single element. οΏ½οΏ½ A 2Γ2 determinant uses ad β bc. οΏ½οΏ½ Non-square matrices do not have determinants.
(1): Determinant of [4] equals 4 β (b) (2): Determinant = (2Γ0) β (5Γβ1) = 5 β (a) (3): Identity matrix determinant = 1 β (c) (4): Matrix (2,3) is 1Γ2, not square β determinant undefined β (d) Thus, Option A is correct. Other options mismatch determinant calculations or matrix classifications.
- οΏ½οΏ½ Option B β Incorrect determinant assignments for matrices A and B.
- οΏ½οΏ½ Option C β Incorrectly treats non-square matrix as determinant-defined.
- οΏ½οΏ½ Option D β Incorrectly matches determinant values and properties.
Used: Substitution
Application: Compute each determinant directly and match systematically.
Final Logic: Correct determinant evaluations uniquely satisfy Option A.
"1Γ1 β itself, 2Γ2 β ad β bc."
3 If A is a 3 Γ 3 square matrix, which of the following logical statements hold true for computing its minors?
1. The minor of (a_{12}) involves evaluating a 2 Γ 2 determinant.
2. Minor (M_{31}) is computed by deleting the 3rd row and the 1st column.
3. The minor of an element is independent of the algebraic sign factor ((-1)^{i+j}).
4. A 2 Γ 3 matrix has perfectly defined minors for all elements.
οΏ½οΏ½ A minor is obtained by deleting one row and one column. οΏ½οΏ½ A cofactor includes the sign factor ((-1)^{i+j}). οΏ½οΏ½ Minors are defined for square matrices in determinant theory.
- For a 3 Γ 3 matrix, deleting one row and one column leaves a 2 Γ 2 determinant. Therefore, the minor of (a_{12}) is obtained by evaluating a 2 Γ 2 determinant. Hence, Statement 1 is correct. β The minor (M_{31}) is obtained by deleting the 3rd row and the 1st column and then evaluating the determinant of the remaining 2 Γ 2 matrix. Therefore, Statement 2 is correct. β The algebraic sign factor ((-1)^{i+j}) is used only while computing the cofactor: Aβα΅’β±Όβ = ((-1)^{i+j}) Mβα΅’β±Όβ Hence, Statement 3 is correct because the sign factor is not a part of the minor. β Statement 4 is incorrect because determinants are defined only for square matrices. Since a 2 Γ 3 matrix is not square, minors are not defined in the context of determinant theory. β Therefore, Statements 1, 2, and 3 are correct.
- οΏ½οΏ½ Option B β Incorrect because it includes Statement 4, which is false.
- οΏ½οΏ½ Option C β Incorrect because it omits Statements 2 and 3, both of which are correct.
- οΏ½οΏ½ Option D β Incorrect because Statement 4 is false.
Used
- Elimination
Application:
- οΏ½οΏ½ Eliminate every option containing Statement 4 because determinant-based minors are defined only for square matrices.
Final Logic:
- οΏ½οΏ½ Minors are obtained by deleting a row and a column, while the sign factor belongs only to cofactors.
- "Minor Deletes; Cofactor Signs."
4 Identify the mathematically INCORRECT statement regarding minor evaluation:
οΏ½οΏ½ Cofactors include sign multipliers. οΏ½οΏ½ Minors are determinants of reduced matrices. οΏ½οΏ½ Minor and cofactor may differ in sign.
Option C is incorrect because a cofactor equals: A_(ij)=(-1)^(i+j)M_(ij) Thus minors and cofactors are not always identical. Option A is correct since deleting one row and column in a 3Γ3 matrix leaves a 2Γ2 determinant. Option B is correct because a minor itself is a determinant. Option D is correct because determinant concepts apply to square matrices.
- οΏ½οΏ½ Option A β Correct definition of minor evaluation.
- οΏ½οΏ½ Option B β A minor is indeed a determinant of smaller order.
- οΏ½οΏ½ Option D β Determinants and minors are defined only for square matrices.
Used: Odd One Out
Application: Identify the option contradicting the cofactor formula.
Final Logic: Only Option C ignores the sign factor in cofactors.
"Cofactor = sign Γ minor."
5 In a mixture problem tracking determinant values, if the minor M_23 evaluates to 13 for a specific matrix element, what is the precisely defined cofactor A_23?
οΏ½οΏ½ Cofactor formula uses sign multiplier. οΏ½οΏ½ For position (2,3), i+j = 5. οΏ½οΏ½ Odd sum gives negative sign.
The cofactor formula is: A_(ij)=(-1)^(i+j)M_(ij) For (2,3): 2+3=5 Since 5 is odd: (-1)^5=-1 Thus: A_(23)=-13 Option B is correct.
- οΏ½οΏ½ Option A β Ignores the negative sign due to odd index sum.
- οΏ½οΏ½ Option C β Cofactors are not reciprocals of minors.
- οΏ½οΏ½ Option D β Incorrect reciprocal form with wrong operation.
Used: Substitution
Application: Apply cofactor sign formula directly.
Final Logic: Odd index sum gives negative cofactor.
"Odd sum β negative cofactor."
6 Under the strict constraint that an element's position yields an even sum of its row and column indices (i.e., i+j is an even integer), how does the cofactor A_ij compare algebraically to its minor M_ij?
οΏ½οΏ½ Cofactor sign depends on i+j. οΏ½οΏ½ Even sum gives positive sign. οΏ½οΏ½ Hence cofactor equals minor.
The cofactor formula is: A_(ij)=(-1)^(i+j)M_(ij) If i+j is even: (-1)^(even)=+1 Therefore: A_(ij)=M_(ij) Hence Option B is correct.
- οΏ½οΏ½ Option A β Opposite signs occur only for odd sums.
- οΏ½οΏ½ Option C β Cofactors are not necessarily zero.
- οΏ½οΏ½ Option D β Minor remains well-defined for square matrices.
Used: Substitution
Application: Substitute even parity into the cofactor formula.
Final Logic: Even index sum produces positive sign.
"Even sum β same sign."
7 Calculate the equated determinant integer (EMI) for the order 2 matrix modeled by Row 1: (-9, 2) and Row 2: (1, -7).
**Correct Answer: A) (-9 * -7) - (2 * 1) = 61**
οΏ½οΏ½ Use determinant formula ad β bc. οΏ½οΏ½ Multiply diagonal elements. οΏ½οΏ½ Subtract cross product.
For matrix: β£[-9, 2; 1, -7]β£ Determinant: (-9)(-7)-(2)(1)63-2=61 Hence Option A is correct.
- οΏ½οΏ½ Option B β Uses incorrect determinant arrangement.
- οΏ½οΏ½ Option C β Uses wrong arithmetic operation.
- οΏ½οΏ½ Option D β Adds instead of subtracting cross product.
Used: Substitution
Application: Directly apply ad β bc formula.
Final Logic: Determinant equals 61.
"2Γ2 determinant = ad β bc."
8 In an order 3 matrix, if you calculate the moving average-like cross-sum: a11A31 + a12A32 + a13*A33, what is the resulting theoretical value?
οΏ½οΏ½ Expansion must use corresponding row cofactors. οΏ½οΏ½ Different row-cofactor combinations give zero. οΏ½οΏ½ This is a determinant property.
The expression: a_(11)A_(31)+a_(12)A_(32)+a_(13)A_(33) uses elements of the first row with cofactors of the third row. According to determinant properties, when elements of one row are multiplied with cofactors of another distinct row, the sum equals zero. Thus, Option C is correct.
- οΏ½οΏ½ Option A β Determinant arises only with matching cofactors from the same row/column.
- οΏ½οΏ½ Option B β No negative determinant property applies here.
- οΏ½οΏ½ Option D β Such expressions do not simplify to 1 generally.
Used: Conceptual/Tonal Matching
Application: Match the expression with determinant expansion identities.
Final Logic: Different-row cofactor expansion gives zero.
"Different row + cofactors = zero."
9 Given a square matrix A with a determinant |A| = 42, what is the probability-based certainty of the value of |A'| (the transpose of matrix A)?
οΏ½οΏ½ Determinant remains unchanged under transpose. οΏ½οΏ½ |A| = |Aβ²|. οΏ½οΏ½ Hence transpose preserves value.
A determinant has the property: β£A^'β£=β£Aβ£ Since: β£Aβ£=42 therefore: β£A^'β£=42 Hence Option C is correct.
- οΏ½οΏ½ Option A β Transpose does not change sign automatically.
- οΏ½οΏ½ Option B β Determinant is not inverted under transpose.
- οΏ½οΏ½ Option D β Determinant remains unchanged, not zero.
Used: Direct Formula Application
Application: Apply transpose property directly.
Final Logic: Determinant remains invariant under transpose.
"Transpose preserves determinant."
10 P10 VECTORS If vector row R1 is interchanged directly with vector row R3 in a matrix A (where initially |A| = 15), what is the newly formed determinant value?
οΏ½οΏ½ Interchanging two rows changes sign. οΏ½οΏ½ Magnitude remains same. οΏ½οΏ½ Determinant becomes negative.
One fundamental determinant property states: If two rows (or columns) are interchanged, the determinant changes sign. Initially: β£Aβ£=15 After interchange: β£Aβ£=-15 Thus Option B is correct.
- οΏ½οΏ½ Option A β Ignores sign change property.
- οΏ½οΏ½ Option C β Determinant becomes zero only for identical/proportional rows.
- οΏ½οΏ½ Option D β Row interchange does not double determinant.
Used: Conceptual/Tonal Matching
Application: Recall determinant sign-change property under row interchange.
Final Logic: Row swap changes only the sign of determinant.
"Swap rows β flip sign."
11 If a coordinate matrix yields a determinant area calculation of exactly 0 (indicating that the 3 points are structurally collinear), the matrix is mathematically defined as:
A matrix with determinant 0 is called singular. Collinear points give zero area. Zero determinant implies non-invertibility.
A matrix is called singular when its determinant equals zero. Here, the determinant used in the area calculation becomes 0 because the points are collinear. In determinant theory, if β£Aβ£=0, then the matrix does not possess an inverse and is classified as singular. Option B is correct because singular matrices always have determinant zero. Option A is incorrect because skew-symmetric matrices satisfy A^'=-A. Option C is incorrect because non-singular matrices require β£Aβ£β 0. Option D is incorrect because identity matrices have determinant 1.
- Option A β Skew-symmetric matrices are defined using transpose properties, not determinant zero.
- Option C β Non-singular matrices must have a non-zero determinant.
- Option D β Identity matrices always have determinant equal to 1.
Used: Elimination
Application: The determinant being exactly zero directly eliminates all options except the singular matrix condition.
Final Logic: β£Aβ£=0βmatrix is singular.
"Zero determinant = Singular certainty."
12 For a matrix P to possess a valid inverse (P^-1), which integral condition must its determinant |P| firmly satisfy to be deemed non-singular?
Inverse exists only for non-singular matrices. Non-singular means determinant is non-zero. Determinant cannot be zero.
A square matrix possesses an inverse only if its determinant is non-zero. Mathematically: A^(-1)Β existsΒ β ββΊβ ββ£Aβ£β 0 Option C is correct because a non-zero determinant guarantees invertibility. Option A is incorrect because determinant need not be exactly 1. Option B is incorrect because determinant zero makes the matrix singular. Option D is incorrect because the determinant can be negative or fractional.
- Option A β Determinant 1 is sufficient but not necessary.
- Option B β Zero determinant implies no inverse exists.
- Option D β Determinants are not restricted to positive integers.
Used: Elimination
Application: Use the inverse existence condition from determinant theory to remove incorrect constraints.
Final Logic: Inverse exists only when determinant is non-zero.
"Non-zero means inverse flows."
13 If the first and third columns of a 3x3 determinant are completely identical in every element, the final evaluated value of the determinant is:
Two identical rows/columns make determinant zero. Determinants depend on linear independence. Identical columns imply dependence.
One of the fundamental properties of determinants states: If any two rows or columns are identical, the determinant equals zero. Since the first and third columns are identical here, the determinant must vanish. Option C is correct. Option A is incorrect because determinants do not double due to identical columns. Option B is incorrect because the determinant is well-defined. Option D is incorrect because the value is not necessarily 1.
- Option A β Identical columns cause determinant collapse, not doubling.
- Option B β Determinant exists for square matrices.
- Option D β No determinant property forces value 1 here.
Used: Contextual/Tonal Matching
Application: The phrase "completely identical" directly signals the determinant-zero property.
Final Logic: Identical columns β determinant equals 0.
"Same rows, determinant goes."
14 If a matrix represents a system where an entire row is composed exclusively of zeros, evaluating its determinant strictly categorizes the matrix as:
Zero row gives determinant zero. Zero determinant implies singularity. Such matrices are non-invertible.
A determinant becomes zero if any row or column contains all zeros. Thus: β£Aβ£=0 Hence, the matrix is singular. Option A is correct. Option B is incorrect because non-singular matrices require non-zero determinant. Option C is incorrect because identity matrices have ones on the diagonal. Option D is incorrect because inverse existence fails.
- Option B β Non-singular matrices cannot have zero determinant.
- Option C β Identity matrices never contain a complete zero row.
- Option D β Singular matrices do not possess inverses.
Used: Elimination
Application: A full zero row immediately implies determinant zero.
Final Logic: Zero row β determinant 0 β singular matrix.
"Zero row, inverse no."
15 If Row 1 elements are exactly proportional to Row 2 elements by a scalar factor k (e.g., R1 = k * R2), the determinant will evaluate to:
Proportional rows are linearly dependent. Linear dependence makes determinant zero. Determinant measures independence.
If one row is a scalar multiple of another row, the rows are linearly dependent. A determinant with proportional rows or columns always evaluates to zero. Option C is correct. Option A and Option D incorrectly treat determinant as directly scaling. Option B has no determinant basis.
- Option A β Determinant does not equal proportionality constant.
- Option B β Reciprocal relation is unrelated here.
- Option D β No squaring rule exists for proportional rows.
Used: Contextual/Tonal Matching
Application: The keyword "proportional" directly connects to determinant-zero property.
Final Logic: Proportional rows β determinant vanishes.
"Proportional rows kill determinant."
16 If the linear operation C1 -> C1 + 5C2 is applied to a matrix bearing an initial determinant D, the new determinant will mathematically evaluate to:
Adding a multiple of one column to another does not change determinant. Determinant remains invariant. Elementary operation preserves value.
One important determinant property states: Adding a multiple of one row/column to another row/column leaves the determinant unchanged. Thus: C_1βC_1+5C_2 does not affect determinant value. Option C is correct. Option A incorrectly assumes multiplication scaling. Option B is not a determinant property. Option D applies only to row interchange.
- Option A β Determinant changes only when an entire row/column is multiplied.
- Option B β Determinants are not altered additively this way.
- Option D β Sign change occurs during interchange, not addition operation.
Used: Substitution
Application: Apply the standard determinant operation rule directly.
Final Logic: Row/column replacement by addition leaves determinant unchanged.
"Add rows freely, determinant stays."
17 If a 3x3 matrix A has a determinant of 10, and a scalar multiple k=3 is multiplied into every single element of matrix A, what is the determinant of the newly formed matrix?
For an nΓn matrix, determinant scales by k^n. Here n=3. So determinant becomes 3^3Γ10.
If every element of an nΓn matrix is multiplied by scalar k, then: β£kAβ£=k^nβ£Aβ£ For a 3Γ3 matrix: β£3Aβ£=3^3Γ10=27Γ10=270 Option C is correct. Option A incorrectly multiplies only once. Option B incorrectly uses 3^2. Option D ignores scaling.
- Option A β Determinant scaling is not linear for 3Γ3 matrices.
- Option B β Uses square scaling instead of cube scaling.
- Option D β Determinant definitely changes after scalar multiplication.
Used: Substitution
Application: Substitute into the determinant scaling formula k^nβ£Aβ£.
Final Logic: 3^3Γ10=270.
"nΓn matrix β kβΏ scaling."
18 Given two 2x2 square matrices A and B, if |A| = -2 and |B| = 6, what is the numerical value of the combined product determinant |AB|?
Determinant of product equals product of determinants. Multiply determinant values directly. (-2)(6)=-12.
For square matrices: β£ABβ£=β£Aβ£β£Bβ£ Given: β£Aβ£=-2,β£Bβ£=6 Therefore: β£ABβ£=(-2)(6)=-12 Option B is correct. Option A, C, and D do not satisfy the determinant product property.
- Option A β Incorrect multiplication result.
- Option C β Does not follow determinant product rule.
- Option D β Ignores the negative sign of β£Aβ£.
Used: Substitution
Application: Directly apply the determinant multiplication property.
Final Logic: β£ABβ£=β£Aβ£β£Bβ£=-12.
"Product matrices β product determinants."
19
If a single column in a 3x3 matrix is expressed as the sum of three algebraic terms, how many distinct determinants can the original determinant be split into?
Determinants are linear in rows/columns. Sum of three terms gives three determinants. Splitting preserves equality.
The determinant summation property states: If elements of one row/column are expressed as sums, the determinant splits into separate determinants corresponding to each term. Since the column contains three summed terms, the determinant splits into three determinants. Option C is correct. Option A ignores splitting. Option B applies only to two-term sums. Option D incorrectly multiplies possibilities.
- Option A β Summation property explicitly creates multiple determinants.
- Option B β Applicable only for binomial splitting.
- Option D β No quadratic expansion occurs.
Used: Contextual/Tonal Matching
Application: The phrase "sum of three terms" directly indicates three determinant components.
Final Logic: Three summed terms β three split determinants.
"Three terms β three determinants."
20
During matrix splitting via the summation property, what must logically happen to the rows or columns that do NOT contain the summed terms?
Only the summed row/column changes. Remaining rows/columns stay identical. This preserves determinant equality.
Under the determinant summation property, splitting occurs only in the row or column containing the sums. All remaining rows and columns remain unchanged and are duplicated exactly across all newly formed determinants. Option B is correct. Option A is incorrect because rows are not divided. Option C is incorrect because no zero replacement occurs. Option D is incorrect because signs remain unchanged.
- Option A β Determinant splitting preserves full structure.
- Option C β Zero substitution is not part of the property.
- Option D β Algebraic signs do not automatically change.
Used: Contextual/Tonal Matching
Application: Focus on the phrase "do NOT contain the summed terms."
Final Logic: Only summed row/column changes; others remain identical.
"Only split row changes."
