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Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 2, Problem 90

Simplify each power of i. i29

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1
Recall that the powers of the imaginary unit \(i\) cycle every 4 powers: \(i^1 = i\), \(i^2 = -1\), \(i^3 = -i\), and \(i^4 = 1\).
To simplify \(i^{29}\), find the remainder when 29 is divided by 4, since the powers repeat every 4.
Calculate \(29 \div 4\) which gives a quotient and a remainder. The remainder determines the equivalent power of \(i\).
Express \(i^{29}\) as \(i^{4k + r}\) where \(k\) is the quotient and \(r\) is the remainder from the division.
Use the fact that \(i^{4k} = (i^4)^k = 1^k = 1\), so \(i^{29} = i^r\), and then substitute the value of \(r\) to find the simplified form.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Imaginary Unit i

The imaginary unit i is defined as the square root of -1, satisfying i² = -1. It is the fundamental building block of complex numbers and is used to extend the real number system to include solutions to equations like x² + 1 = 0.
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Powers of i and Their Cyclic Pattern

Powers of i repeat in a cycle of four: i¹ = i, i² = -1, i³ = -i, and i⁴ = 1. This pattern repeats for higher powers, so simplifying i raised to any integer power involves finding the remainder when the exponent is divided by 4.
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Modular Arithmetic for Exponent Simplification

Modular arithmetic helps simplify powers by reducing the exponent modulo 4 in this context. For example, to simplify i²⁹, compute 29 mod 4 = 1, so i²⁹ = i¹ = i. This technique streamlines calculations involving cyclic patterns.
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