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If (a2+1)22a-i = x + iy, what is the value of x2 + y2? - Mathematics

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Question

If `(a^2 + 1)^2/(2a - i)` = x + iy, what is the value of x2 + y2?

Sum

Solution

Given that: `(a^2 + 1)^2/(2a - i)` = x + iy   ......(i)

Taking conjugate on both sides

⇒ `(a^2 + 1)^2/(2a + i)` = x – iy   ......(ii)

Multiplying equation (i) and (ii) we have

`((a^2 + 1)^2(a^2 + 1)^2)/((2a - i)(2a + i))` = x2 + y2

⇒ `(a^2 + 1)^4/(4a^2 - i^2)` = x2 + y2

⇒  `(a^2 + 1)^4/(4a^2 + 1)` = x2 + y2

Hence, the value of x2 + y2 = `(a^2 + 1)^4/(4a^2 + 1)`.

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Chapter 5: Complex Numbers and Quadratic Equations - Exercise [Page 94]

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NCERT Exemplar Mathematics [English] Class 11
Chapter 5 Complex Numbers and Quadratic Equations
Exercise | Q 30 | Page 94

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