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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 101

Work each problem. Show that √2/2 + √2/2 i is a square root of i.

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1
Express the given complex number as \(z = \frac{\sqrt{2}}{2} + \frac{\sqrt{2}}{2}i\).
Recall that to show \(z\) is a square root of \(i\), we need to verify that \(z^2 = i\).
Calculate \(z^2\) by using the formula for squaring a complex number: \((a + bi)^2 = a^2 + 2abi + (bi)^2\) where \(a = \frac{\sqrt{2}}{2}\) and \(b = \frac{\sqrt{2}}{2}\).
Substitute the values of \(a\) and \(b\) into the formula and simplify each term carefully, remembering that \(i^2 = -1\).
After simplification, compare the result of \(z^2\) with \(i\) to confirm whether they are equal, thus proving \(z\) is a square root of \(i\).

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Key Concepts

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

Complex Numbers and Imaginary Unit

Complex numbers are numbers in the form a + bi, where a and b are real numbers and i is the imaginary unit with the property i² = -1. Understanding how to work with i is essential for manipulating and interpreting expressions involving complex numbers.
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Square Roots of Complex Numbers

Finding the square root of a complex number involves determining a complex number which, when squared, equals the original number. This requires knowledge of how to square complex numbers and equate real and imaginary parts to verify the root.
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Multiplication of Complex Numbers in Standard Form

Multiplying complex numbers in the form a + bi involves using the distributive property and the fact that i² = -1. This process helps verify if a given complex number squared equals another complex number, such as checking if (√2/2 + √2/2 i)² equals i.
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