मराठी

If A, B, C Are in A.P., Then the Determinant ∣ ∣ ∣ ∣ X + 2 X + 3 X + 2 a X + 3 X + 4 X + 2 B X + 4 X + 5 X + 2 C ∣ ∣ ∣ ∣ (A) 0 (B) 1 (C) X (D) 2x - Mathematics

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प्रश्न

If a, b, c are in A.P., then the determinant
\[\begin{vmatrix}x + 2 & x + 3 & x + 2a \\ x + 3 & x + 4 & x + 2b \\ x + 4 & x + 5 & x + 2c\end{vmatrix}\]

पर्याय

  • 0

  • 1

  • x

  • 2x

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उत्तर


\[\begin{vmatrix} x + 2 & x + 3 & x + 2a\\x + 3 & x + 4 & x + 2b\\x + 4 & x + 5 & x + 2c \end{vmatrix}\]
\[ = \begin{vmatrix} 0 & 0 & 2\left( a + c - 2b \right)\\x + 3 & x + 4 & x + 2b\\x + 4 & x + 5 & x + 2c \end{vmatrix} \left[\text{ Applying }R_1 \to R_1 + R_3 - R_2 , R_1 \to R_1 - R_2 \right]\]
\[ = \begin{vmatrix} 0 & 0 & 0\\x + 3 & x + 4 & x + 2b\\x + 4 & x + 5 & x + 2c \end{vmatrix} \left[ \because\text{ a, b, c are in A . P . }\right]\]
\[ = 0\]

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पाठ 6: Determinants - Exercise 6.7 [पृष्ठ ९४]

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आरडी शर्मा Mathematics [English] Class 12
पाठ 6 Determinants
Exercise 6.7 | Q 18 | पृष्ठ ९४

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