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if A(1) ,B(1),C(1) ……. are respectively...

if `A_(1) ,B_(1),C_(1) …….` are respectively the cofactors of the elements `a_(1) ,b_(1),c_(1)……` of the determinant
`Delta = |{:(a_(1),,b_(1),,c_(1)),(a_(2),,b_(2),,c_(2)),(a_(3),,b_(3),,c_(3)):}|, Delta ne 0 ` then the value of `|{:(B_(2),,C_(2)),(B_(3),,C_(3)):}|` is equal to

A

`a_(1)^(2)Delta`

B

`a_(1)Delta`

C

`a_(1)Delta^(2)`

D

`a_(1)^(2)Delta^(2)`

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To solve the given problem, we need to find the value of the determinant \( |{:(B_2, C_2),(B_3, C_3):}| \) where \( B_2, C_2, B_3, C_3 \) are the cofactors of the elements \( b_2, c_2, b_3, c_3 \) respectively from the determinant \( \Delta = |{:(a_1, b_1, c_1),(a_2, b_2, c_2),(a_3, b_3, c_3):}| \). ### Step 1: Write the determinant The determinant is given as: \[ \Delta = |{:(a_1, b_1, c_1),(a_2, b_2, c_2),(a_3, b_3, c_3):}| \] ### Step 2: Calculate the cofactors The cofactors \( B_2, C_2, B_3, C_3 \) can be calculated as follows: - **Cofactor \( B_2 \)**: \[ B_2 = (-1)^{2+1} |{:(a_1, c_1),(a_3, c_3):}| = |{:(a_1, c_1),(a_3, c_3):}| = a_1 c_3 - a_3 c_1 \] - **Cofactor \( C_2 \)**: \[ C_2 = (-1)^{2+2} |{:(a_1, b_1),(a_3, b_3):}| = |{:(a_1, b_1),(a_3, b_3):}| = a_1 b_3 - a_3 b_1 \] - **Cofactor \( B_3 \)**: \[ B_3 = (-1)^{3+2} |{:(a_1, c_1),(a_2, c_2):}| = -|{:(a_1, c_1),(a_2, c_2):}| = - (a_1 c_2 - a_2 c_1) = a_2 c_1 - a_1 c_2 \] - **Cofactor \( C_3 \)**: \[ C_3 = (-1)^{3+3} |{:(a_1, b_1),(a_2, b_2):}| = |{:(a_1, b_1),(a_2, b_2):}| = a_1 b_2 - a_2 b_1 \] ### Step 3: Set up the determinant of cofactors Now we need to find the determinant: \[ |{:(B_2, C_2),(B_3, C_3):}| \] Substituting the values of \( B_2, C_2, B_3, C_3 \): \[ = |{:(a_1 c_3 - a_3 c_1, a_1 b_3 - a_3 b_1),(a_2 c_1 - a_1 c_2, a_1 b_2 - a_2 b_1):}| \] ### Step 4: Calculate the determinant Using the determinant formula for a 2x2 matrix: \[ |{:(x_1, y_1),(x_2, y_2):}| = x_1 y_2 - x_2 y_1 \] we can compute: \[ = (a_1 c_3 - a_3 c_1)(a_1 b_2 - a_2 b_1) - (a_2 c_1 - a_1 c_2)(a_1 b_3 - a_3 b_1) \] ### Step 5: Simplify the expression After expanding and simplifying the above expression, we will get: \[ = a_1^2 (c_3 b_2 - c_1 b_3) + a_2 (c_1 b_3 - c_3 b_1) + a_3 (c_2 b_1 - c_1 b_2) \] ### Conclusion Thus, the final value of the determinant \( |{:(B_2, C_2),(B_3, C_3):}| \) is: \[ = \Delta \] where \( \Delta \) is the original determinant.

To solve the given problem, we need to find the value of the determinant \( |{:(B_2, C_2),(B_3, C_3):}| \) where \( B_2, C_2, B_3, C_3 \) are the cofactors of the elements \( b_2, c_2, b_3, c_3 \) respectively from the determinant \( \Delta = |{:(a_1, b_1, c_1),(a_2, b_2, c_2),(a_3, b_3, c_3):}| \). ### Step 1: Write the determinant The determinant is given as: \[ \Delta = |{:(a_1, b_1, c_1),(a_2, b_2, c_2),(a_3, b_3, c_3):}| \] ...
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