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Simplify the following and express in the form a + ib: (1 + 3i)2 (3 + i)

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Question

Simplify the following and express in the form a + ib:

(1 + 3i)2 (3 + i)

Sum
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Solution

(1 + 3i)2 (3 + i)
= (1 + 6i + 9i2)(3 + i)
= (1 + 6i – 9)(3 + i)        ...[∵ i2 = – 1]
= (– 8 + 6i)(3 + i)
=  – 24 – 8i + 18i + 6i2
= – 24 + 10i +6(– 1)
= –24 + 10i – 6
= – 30 + 10i

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Chapter 3: Complex Numbers - MISCELLANEOUS EXERCISE - 3 [Page 42]

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Balbharati Mathematics and Statistics 1 (Commerce) [English] Standard 11 Maharashtra State Board
Chapter 3 Complex Numbers
MISCELLANEOUS EXERCISE - 3 | Q 3) v) | Page 42

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