Identify each number as real, complex, pure imaginary, or nonreal complex. (More than one of these descriptions will apply.) -6 -2i
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- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
The Imaginary Unit
Problem 39a
Textbook Question
Find each product or quotient. Simplify the answers. √-6 * √-2 / √3
Verified step by step guidance1
Recognize that the problem involves square roots of negative numbers, which means we will be working with imaginary numbers. Recall that \(\sqrt{-a} = i\sqrt{a}\), where \(i\) is the imaginary unit with the property \(i^2 = -1\).
Rewrite each square root of a negative number using the imaginary unit \(i\): \(\sqrt{-6} = i\sqrt{6}\) and \(\sqrt{-2} = i\sqrt{2}\). The expression becomes \(\frac{(i\sqrt{6})(i\sqrt{2})}{\sqrt{3}}\).
Multiply the numerators: \((i\sqrt{6})(i\sqrt{2}) = i \cdot i \cdot \sqrt{6} \cdot \sqrt{2} = i^2 \sqrt{12}\). Since \(i^2 = -1\), this simplifies to \(-\sqrt{12}\).
Simplify \(\sqrt{12}\) by factoring it into \(\sqrt{4 \times 3} = \sqrt{4} \times \sqrt{3} = 2\sqrt{3}\). So the numerator becomes \(-2\sqrt{3}\).
Now the expression is \(\frac{-2\sqrt{3}}{\sqrt{3}}\). Since \(\sqrt{3}\) appears in both numerator and denominator, simplify by canceling \(\sqrt{3}\), leaving \(-2\) as the simplified result.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Properties of Square Roots
Square roots represent the principal non-negative root of a number. For positive numbers, √a * √b = √(a*b). However, when dealing with negative numbers under the square root, the concept extends to complex numbers, since the square root of a negative number involves imaginary units.
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Imaginary Numbers and the Imaginary Unit i
The imaginary unit i is defined as √-1. When taking the square root of negative numbers, express them as √(-1 * positive number) = i√(positive number). This allows simplification of roots of negative numbers into a form involving i, which is essential for working with complex numbers.
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Simplifying Expressions with Radicals and Complex Numbers
To simplify expressions involving radicals and complex numbers, first rewrite all radicals with negative radicands using i, then multiply or divide the expressions by combining like terms. Finally, simplify the resulting expression by reducing fractions and combining radicals where possible.
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