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Find the value of 2x4 + 5x3 + 7x2 – x + 41, when x = i-2-3i.

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प्रश्न

Find the value of 2x4 + 5x3 + 7x2 – x + 41, when x = `-2 - sqrt(3)"i"`.

योग
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उत्तर

x + 2 = `- sqrt(3)"i"` ⇒ x2 + 4x + 7 = 0

Therefore, 2x4 + 5x3 + 7x2 – x + 41

= (x2 + 4x + 7)(2x2 – 3x + 5) + 6

= 0 × (2x2 – 3x + 5) + 6

= 6

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अध्याय 5: Complex Numbers and Quadratic Equations - Solved Examples [पृष्ठ ८१]

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एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 5 Complex Numbers and Quadratic Equations
Solved Examples | Q 11 | पृष्ठ ८१

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