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Consider the system of equations {:(2x...

Consider the system of equations
`{:(2x+lambday+6z=8),(x+2y+muz=5),(x+y+3z=4):}`
The system of equations has :
No solution if :

A

1)`lambda=2, mu=3`

B

2)`lambdane 2 , mu=3`

C

3)`lambda ne 2, mu ne 3 `

D

4)`lambda =2 , mu in R `

Text Solution

AI Generated Solution

The correct Answer is:
To determine the conditions under which the given system of equations has no solution, we will follow these steps: ### Step 1: Write the System of Equations The given system of equations is: 1. \( 2x + \lambda y + 6z = 8 \) 2. \( x + 2y + \mu z = 5 \) 3. \( x + y + 3z = 4 \) ### Step 2: Form the Coefficient Matrix and Calculate the Determinant The coefficient matrix \( A \) is: \[ A = \begin{bmatrix} 2 & \lambda & 6 \\ 1 & 2 & \mu \\ 1 & 1 & 3 \end{bmatrix} \] To find the condition for no solution, we need to calculate the determinant \( \Delta \) of this matrix and set it to zero: \[ \Delta = \begin{vmatrix} 2 & \lambda & 6 \\ 1 & 2 & \mu \\ 1 & 1 & 3 \end{vmatrix} \] ### Step 3: Expand the Determinant We can expand the determinant along the first row: \[ \Delta = 2 \begin{vmatrix} 2 & \mu \\ 1 & 3 \end{vmatrix} - \lambda \begin{vmatrix} 1 & \mu \\ 1 & 3 \end{vmatrix} + 6 \begin{vmatrix} 1 & 2 \\ 1 & 1 \end{vmatrix} \] Calculating the 2x2 determinants: 1. \( \begin{vmatrix} 2 & \mu \\ 1 & 3 \end{vmatrix} = (2)(3) - (1)(\mu) = 6 - \mu \) 2. \( \begin{vmatrix} 1 & \mu \\ 1 & 3 \end{vmatrix} = (1)(3) - (1)(\mu) = 3 - \mu \) 3. \( \begin{vmatrix} 1 & 2 \\ 1 & 1 \end{vmatrix} = (1)(1) - (1)(2) = 1 - 2 = -1 \) Substituting these back into the determinant: \[ \Delta = 2(6 - \mu) - \lambda(3 - \mu) + 6(-1) \] \[ = 12 - 2\mu - 3\lambda + \lambda\mu - 6 \] \[ = \lambda\mu - 3\lambda - 2\mu + 6 \] ### Step 4: Set the Determinant to Zero For the system to have no solution, we set \( \Delta = 0 \): \[ \lambda\mu - 3\lambda - 2\mu + 6 = 0 \] ### Step 5: Rearranging the Equation Rearranging the equation gives: \[ \lambda\mu - 3\lambda - 2\mu + 6 = 0 \] This can be factored or analyzed to find conditions on \( \lambda \) and \( \mu \). ### Step 6: Analyze the Conditions From the determinant condition, we can see that: 1. If \( \lambda = 2 \), then the equation simplifies to \( 2\mu - 6 = 0 \) which gives \( \mu = 3 \). 2. If \( \mu = 3 \), then the equation simplifies to \( \lambda(3) - 3\lambda - 6 = 0 \) which gives \( \lambda = 2 \). ### Step 7: Check the Second Condition For the system to have no solution, at least one of the determinants \( \Delta_x, \Delta_y, \Delta_z \) must be non-zero when \( \Delta = 0 \). ### Conclusion The system of equations has no solution if: - \( \lambda \neq 2 \) and \( \mu = 3 \). Thus, the correct answer is: **The system has no solution if \( \lambda \neq 2 \) and \( \mu = 3 \).**
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