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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 23a

Write each number as the product of a real number and i. √-10

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1
Recall that the imaginary unit \(i\) is defined as \(i = \sqrt{-1}\).
Express the square root of a negative number in terms of \(i\): \(\sqrt{-10} = \sqrt{10 \times (-1)}\).
Use the property of square roots to separate the factors: \(\sqrt{10 \times (-1)} = \sqrt{10} \times \sqrt{-1}\).
Substitute \(\sqrt{-1}\) with \(i\): \(\sqrt{10} \times i\).
Therefore, \(\sqrt{-10}\) can be written as the product of the real number \(\sqrt{10}\) and \(i\).

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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 allows us to express the square roots of negative numbers in terms of real numbers multiplied by i.
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Powers of i

Simplifying Square Roots of Negative Numbers

To simplify the square root of a negative number, separate it into the square root of the negative part and the positive part, such as √(-a) = √(-1) × √a = i√a, where a is positive.
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Square Roots of Negative Numbers

Expressing Complex Numbers in Standard Form

Complex numbers are often written as a product of a real number and i when dealing with purely imaginary numbers. For example, √-10 can be expressed as (√10) × i, showing the real magnitude and the imaginary unit.
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Multiplying Complex Numbers