In Exercises 9–20, find each product and write the result in standard form. (2 + 3i)²
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- 0. Review of College Algebra4h 45m
- 1. Measuring Angles40m
- 2. Trigonometric Functions on Right Triangles2h 5m
- 3. Unit Circle1h 19m
- 4. Graphing Trigonometric Functions1h 19m
- 5. Inverse Trigonometric Functions and Basic Trigonometric Equations1h 41m
- 6. Trigonometric Identities and More Equations2h 34m
- 7. Non-Right Triangles1h 38m
- 8. Vectors2h 25m
- 9. Polar Equations2h 5m
- 10. Parametric Equations1h 6m
- 11. Graphing Complex Numbers1h 7m
11. Graphing Complex Numbers
Graphing Complex Numbers
Problem 31
Textbook Question
In Exercises 29–36, simplify and write the result in standard form. ____ √−108
Verified step by step guidance1
Recognize that the expression involves the square root of a negative number, which means the result will be a complex number. Recall that \(\sqrt{-a} = \sqrt{a} \times i\), where \(i\) is the imaginary unit with the property \(i^2 = -1\).
Rewrite the expression \(\sqrt{-108}\) as \(\sqrt{108} \times i\) to separate the imaginary unit from the real number under the root.
Simplify \(\sqrt{108}\) by factoring 108 into its prime factors or perfect squares. For example, \(108 = 36 \times 3\), and since \(\sqrt{36} = 6\), you can write \(\sqrt{108} = \sqrt{36 \times 3} = 6\sqrt{3}\).
Substitute back to get the expression in terms of \(i\): \(\sqrt{-108} = 6\sqrt{3} \times i\).
Write the final answer in standard form for complex numbers, which is \(a + bi\). Since there is no real part here, the expression is \(0 + 6\sqrt{3}i\).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Simplifying Square Roots of Negative Numbers
When simplifying the square root of a negative number, recognize that it involves imaginary numbers. The square root of a negative number can be expressed as the product of the imaginary unit 'i' (where i² = -1) and the square root of the corresponding positive number.
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Imaginary Roots with the Square Root Property
Prime Factorization for Simplifying Radicals
To simplify a square root, break down the number inside the root into its prime factors. Pair factors to extract them from under the root, simplifying the expression. For example, √108 can be factored into √(36 × 3) = 6√3.
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Factoring
Standard Form of Complex Numbers
The standard form of a complex number is a + bi, where 'a' is the real part and 'b' is the imaginary coefficient. After simplifying the radical, express the result in this form to clearly separate real and imaginary components.
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Complex Numbers In Polar Form
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