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Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
All textbooksLial 13th EditionCh. 1 - Equations and InequalitiesProblem 61a
Chapter 2, Problem 61a

Find each product. Write answers in standard form. (3+i)(3-i)

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1
Recognize that the expression is a product of two complex conjugates: \((3 + i)\) and \((3 - i)\).
Use the formula for the product of conjugates: \((a + b)(a - b) = a^2 - b^2\), where \(a = 3\) and \(b = i\).
Calculate \(a^2\): \(3^2 = 9\).
Calculate \(b^2\): \(i^2\). Recall that \(i^2 = -1\).
Substitute these values into the formula: \(9 - (-1)\), which simplifies to \(9 + 1\).

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Key Concepts

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

Complex Numbers

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 complex numbers is essential for operations like addition, multiplication, and finding products.
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Multiplication of Complex Numbers

Multiplying complex numbers involves using the distributive property (FOIL method) and applying the rule i² = -1 to simplify. For example, (3 + i)(3 - i) requires multiplying each term and combining like terms carefully.
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Standard Form of Complex Numbers

The standard form of a complex number is a + bi, where a and b are real numbers. After multiplication, the result should be simplified and expressed in this form, separating the real and imaginary parts clearly.
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