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The real value of ‘a’ for which 3i3 – 2ai2 + (1 – a)i + 5 is real is ______. - Mathematics

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प्रश्न

The real value of ‘a’ for which 3i3 – 2ai2 + (1 – a)i + 5 is real is ______.

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उत्तर

The real value of ‘a’ for which 3i3 – 2ai2 + (1 – a)i + 5 is real is – 2.

Explanation:

3i3 – 2ai2 + (1 – a)i + 5 = –3i + 2a + 5 + (1 – a)i

= 2a + 5 + (–a – 2)i

which is real if –a – 2 = 0

i.e. a = –2.

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अध्याय 5: Complex Numbers and Quadratic Equations - Solved Examples [पृष्ठ ८३]

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एनसीईआरटी एक्झांप्लर Mathematics [English] Class 11
अध्याय 5 Complex Numbers and Quadratic Equations
Solved Examples | Q 16.(i) | पृष्ठ ८३

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