- AIf a = 3, then the system has infinitely many solutions for all values of and .
- BIf a 3, then the system has a unique solution for all values of and .
- CIf += 0, then the system has infinitely many solutions for a = 3.
- DIf + 0, then the system has no solution for a = -3.
View written solutionFree
Correct answer: B, C, D
The given system of linear equations is:
ax + 2y = λ3x - 2y = μ
We can analyze the nature of the solutions using the determinant of the coefficient matrix.
Step 1: Find the determinant of the coefficient matrix.
The coefficient matrix A for the system is:
The determinant of A is:
Step 2: Analyze the condition for a unique solution.
A system of linear equations has a unique solution if and only if the determinant of its coefficient matrix is non-zero, i.e., det(A) ≠ 0.
So, if a ≠ -3, the system has a unique solution for any values of λ and μ.
- Evaluating Option B: "If
a ≠ -3, then the system has a unique solution for all values ofλandμ." This statement is correct based on our analysis.
Step 3: Analyze the case when det(A) = 0.
If det(A) = 0, the system will have either infinitely many solutions or no solution. This occurs when:
Let's substitute a = -3 into the system of equations:
-3x + 2y = λ3x - 2y = μ
Step 4: Determine the conditions for infinitely many solutions or no solution.
We can add the two equations to eliminate the variables:
This equation provides the condition for the consistency of the system.
-
Case 4.1: Infinitely many solutions The system is consistent and has infinitely many solutions if the condition
0 = λ + μis satisfied. Ifλ + μ = 0, thenμ = -λ. The second equation3x - 2y = μbecomes3x - 2y = -λ, which is equivalent to-1(-3x + 2y) = -1(λ), so it is the same as the first equation. The two equations are dependent, representing the same line, and thus have infinitely many solutions.- Evaluating Option C: "If
λ + μ = 0, then the system has infinitely many solutions fora = -3." This statement is correct. - Evaluating Option A: "If
a = -3, then the system has infinitely many solutions for all values ofλandμ." This statement is incorrect because it requires the specific conditionλ + μ = 0.
- Evaluating Option C: "If
-
Case 4.2: No solution The system is inconsistent and has no solution if the condition
0 = λ + μleads to a contradiction. This happens ifλ + μ ≠ 0. In this case, we have0 = (a non-zero value), which is impossible. Geometrically, the two lines are parallel and distinct.- Evaluating Option D: "If
λ + μ ≠ 0, then the system has no solution fora = -3." This statement is correct.
- Evaluating Option D: "If
Conclusion
Based on the step-by-step analysis, the correct statements are B, C, and D.
More from Matrices and Determinants
- Let X and Y be two arbitrary, 3 3, non-zero, skew-symmetric matrices and Z be an arbitrary 3 3, non-zero, symmetric matrix. Then which of the following matrices is(are) skew symmetric?2015 · Multiple correct
- Which of the following values of satisfy the equation …2015 · Multiple correct
- Let M be a 2 2 symmetric matrix with integer entries. Then, M is invertible, if2014 · Multiple correct
- Let M and N be two 3 3 matrices such that MN = NM. Further, if M N2 and M2 = N4, then2014 · Multiple correct
- For 3 × 3 matrices M and N, which of the following statement(s) is(are) NOT correct?2013 · Multiple correct
- Let be a complex cube root of unity with 1 and P = [pij] be a n n matrix with pij = i + j. Then P2 0, when n = ?2013 · Multiple correct
- Let be a 3 3 matrix and let , where for . If the determinant of P is 2, then the determinant of the matrix Q is2012 · MCQ
- If P is a 3 3 matrix such that PT = 2P + I, where PT is the transpose of P and I is the 3 3 identity matrix, then there exists a column matrix …2012 · MCQ