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Without expanding the determinant, prove that sabcsbcascab|sa2b2+c2sb2c2+a2sc2a2+b2| = 0 - Mathematics

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प्रश्न

Without expanding the determinant, prove that `|("s", "a"^2, "b"^2 + "c"^2),("s", "b"^2, "c"^2 + "a"^2),("s", "c"^2, "a"^2 + "b"^2)|` = 0

बेरीज

उत्तर

`|("s", "a"^2, "b"^2 + "c"^2),("s", "b"^2, "c"^2 + "a"^2),("s", "c"^2, "a"^2 + "b"^2)| = "s"|(1, "a"^2, "b"^2 + "c"^2),(1, "b"^2, "c"^2 + "a"^2),(1, "c"^2, "a"^2 + "b"^2)|`

= `"s"|(1, "a"^2, "a"^2 + "b"^2 + "c"^2),(1, "b"^2, "a"^2 + "b"^2 + "c"^2),(1, "c"^2, "a"^2 + "b"^2 + "c"^2)|  "C"_3 -> "C"_3 + "C"_2`

= `"s"("a"^2 + "b"^2 + "c"^2)|(1, "a"^2, 1),(1, "b"^2, 1),(1, "c"^2, 1)|`

= s (a2 + b2 + c2) × 0

Since two columns are equal.

= 0

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Determinants
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पाठ 7: Matrices and Determinants - Exercise 7.2 [पृष्ठ २८]

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सामाचीर कलवी Mathematics - Volume 1 and 2 [English] Class 11 TN Board
पाठ 7 Matrices and Determinants
Exercise 7.2 | Q 1 | पृष्ठ २८

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