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Write the Value of the Determinant ∣ ∣ ∣ ∣ a 1 B + C B 1 C + a C 1 a + B ∣ ∣ ∣ ∣ - Mathematics

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प्रश्न

Write the value of the determinant 

\[\begin{vmatrix}a & 1 & b + c \\ b & 1 & c + a \\ c & 1 & a + b\end{vmatrix} .\]

 

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उत्तर

\[\text{ Let }∆ = \begin{vmatrix}a & 1 & b + c \\ b & 1 & c + a \\ c & 1 & a + b\end{vmatrix} \] 
\[ = \begin{vmatrix} a + b + c & 1 & b + c\\a + b + c & 1 & c + a\\a + b + c & 1 & a + b \end{vmatrix} \left[\text{ Applying }C_1 \to C_1 + C_3 \right]\] 
\[ = a + b + c \begin{vmatrix} 1 & 1& b + c\\1 & 1 & c + a\\1 & 1 & a + b \end{vmatrix}\] 
\[ = \left( a + b + c \right) \times 0\] 
\[ = 0\] 

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अध्याय 6: Determinants - Exercise 6.6 [पृष्ठ ९०]

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आरडी शर्मा Mathematics [English] Class 12
अध्याय 6 Determinants
Exercise 6.6 | Q 7 | पृष्ठ ९०

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