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If |(a^2,b^2,c^2),((a+lambda)^2,(b+lambd...

If `|(a^2,b^2,c^2),((a+lambda)^2,(b+lambda)^2,(c+lambda)^2),((a-lambda)^2,(b-lamda)^2,(c-lambda)^2)|=klambda|(a^2,b^2,c^2),(a,b,c),(1,1,1)|lambda!=0` then `k` is equal to : (A) `4 lambda abc ` (B) `-4 lambda abc ` (C) `4 lambda^2` (D) `-4 lambda^2`

A

`4 lambda abc`

B

`- 4 lambda^(2)`

C

`4 lambda^(2)`

D

`- 4 lambda abc`

Text Solution

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To solve the given problem, we need to evaluate the determinant and find the value of \( k \) in the equation: \[ \left| \begin{array}{ccc} a^2 & b^2 & c^2 \\ (a+\lambda)^2 & (b+\lambda)^2 & (c+\lambda)^2 \\ (a-\lambda)^2 & (b-\lambda)^2 & (c-\lambda)^2 \end{array} \right| = k\lambda \left| \begin{array}{ccc} a^2 & b^2 & c^2 \\ a & b & c \\ 1 & 1 & 1 \end{array} \right| \] ### Step 1: Expand the Determinant We start by expanding the determinant on the left-hand side. \[ \left| \begin{array}{ccc} a^2 & b^2 & c^2 \\ (a+\lambda)^2 & (b+\lambda)^2 & (c+\lambda)^2 \\ (a-\lambda)^2 & (b-\lambda)^2 & (c-\lambda)^2 \end{array} \right| \] ### Step 2: Simplify the Second and Third Rows We can simplify the second and third rows by performing row operations. Let's denote: - \( R_2 = (a+\lambda)^2, (b+\lambda)^2, (c+\lambda)^2 \) - \( R_3 = (a-\lambda)^2, (b-\lambda)^2, (c-\lambda)^2 \) Now, we can perform the operation \( R_2 - R_3 \): \[ R_2 - R_3 = \left( (a+\lambda)^2 - (a-\lambda)^2, (b+\lambda)^2 - (b-\lambda)^2, (c+\lambda)^2 - (c-\lambda)^2 \right) \] Calculating each term: \[ (a+\lambda)^2 - (a-\lambda)^2 = 4a\lambda \] \[ (b+\lambda)^2 - (b-\lambda)^2 = 4b\lambda \] \[ (c+\lambda)^2 - (c-\lambda)^2 = 4c\lambda \] Thus, the new second row becomes: \[ (4a\lambda, 4b\lambda, 4c\lambda) \] ### Step 3: Update the Determinant Now, we have: \[ \left| \begin{array}{ccc} a^2 & b^2 & c^2 \\ 4a\lambda & 4b\lambda & 4c\lambda \\ (a-\lambda)^2 & (b-\lambda)^2 & (c-\lambda)^2 \end{array} \right| \] ### Step 4: Factor Out Common Terms We can factor out \( 4\lambda \) from the second row: \[ = 4\lambda \left| \begin{array}{ccc} a^2 & b^2 & c^2 \\ a & b & c \\ (a-\lambda)^2 & (b-\lambda)^2 & (c-\lambda)^2 \end{array} \right| \] ### Step 5: Simplify the Third Row Next, we can simplify the third row as follows: \[ R_3 = (a-\lambda)^2, (b-\lambda)^2, (c-\lambda)^2 \] We can express this as: \[ R_3 = (a^2 - 2a\lambda + \lambda^2, b^2 - 2b\lambda + \lambda^2, c^2 - 2c\lambda + \lambda^2) \] ### Step 6: Perform Row Operations Again Now, we perform another row operation \( R_3 + 2R_2 - R_1 \): This will help us eliminate the \( a^2, b^2, c^2 \) terms in \( R_3 \). ### Step 7: Calculate the Determinant After performing these operations, we will find that the determinant simplifies to: \[ = 4\lambda^3 \left| \begin{array}{ccc} 1 & 1 & 1 \\ a & b & c \\ a^2 & b^2 & c^2 \end{array} \right| \] ### Step 8: Relate to the Right Side The determinant on the right-hand side is: \[ k\lambda \left| \begin{array}{ccc} a^2 & b^2 & c^2 \\ a & b & c \\ 1 & 1 & 1 \end{array} \right| \] ### Step 9: Equate and Solve for \( k \) Setting both sides equal gives: \[ 4\lambda^3 = k\lambda \] Dividing both sides by \( \lambda \) (since \( \lambda \neq 0 \)): \[ 4\lambda^2 = k \] Thus, we find: \[ k = 4\lambda^2 \] ### Final Answer The value of \( k \) is: \[ \boxed{4\lambda^2} \]
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