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Ch. R - Review of Basic Concepts
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 1, Problem 79

Evaluate each expression. (-4)1/2

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1
Recognize that the expression \((-4)^{1/2}\) represents the square root of -4, since an exponent of \(\frac{1}{2}\) means taking the square root.
Recall that the square root of a negative number is not a real number, but an imaginary number involving \(i\), where \(i = \sqrt{-1}\).
Rewrite \((-4)^{1/2}\) as \(\sqrt{-4} = \sqrt{4 \times (-1)}\).
Use the property of square roots to separate the factors: \(\sqrt{4 \times (-1)} = \sqrt{4} \times \sqrt{-1}\).
Evaluate \(\sqrt{4} = 2\) and \(\sqrt{-1} = i\), so the expression simplifies to \$2i$.

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Key Concepts

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

Rational Exponents

Rational exponents represent roots and powers simultaneously. For example, an exponent of 1/2 means the square root of the base. Understanding how to interpret and manipulate rational exponents is essential for evaluating expressions like (-4)^(1/2).
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Square Roots of Negative Numbers

The square root of a negative number is not a real number but an imaginary number. Specifically, the square root of -1 is defined as i, the imaginary unit. This concept is crucial when evaluating expressions like (-4)^(1/2), which involves the square root of a negative number.
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Complex Numbers

Complex numbers extend the real number system to include imaginary numbers, expressed as a + bi, where i is the imaginary unit. Understanding complex numbers allows one to work with and simplify expressions involving roots of negative numbers, such as (-4)^(1/2) = 2i.
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