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महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता ११ वी

Find a and b if (a + ib) (1 + i) = 2 + i

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प्रश्न

Find a and b if (a + ib) (1 + i) = 2 + i

बेरीज
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उत्तर

(a + ib) (1 + i) = 2 + i

∴ a + ai + bi + bi2 = 2 + i

∴ a + (a + b)i + b(–1) = 2 + i     …[∵ i2 = – 1]

∴ (a – b) + (a + b)i = 2 + i

Equating real and imaginary parts, we get

a – b = 2    ...(i)

a + b = 1  ...(ii)

Adding equation (i) and (ii), we get

2a = 3

∴ a = `3/2`

Substituting a = `3/2` in (ii),we get

`3/2 +"b"` = 1

∴ b = `1 - 3/2 = -1/2`

a = `3/2`and b = `-1/2`.

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पाठ 1: Complex Numbers - Exercise 1.1 [पृष्ठ ६]

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