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Ch. 1 - Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 25

Divide and express the result in standard form. 8i/(4 - 3i)

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Identify the problem: You need to divide the complex number \$8i\( by the complex number \)(4 - 3i)\( and express the result in standard form, which is \)a + bi\( where \)a\( and \)b$ are real numbers.
To divide complex numbers, multiply the numerator and denominator by the conjugate of the denominator. The conjugate of \((4 - 3i)\) is \((4 + 3i)\). So multiply both numerator and denominator by \((4 + 3i)\):
\[\frac{8i}{4 - 3i} \times \frac{4 + 3i}{4 + 3i}\]
Use the distributive property (FOIL) to expand both the numerator and the denominator:
- Numerator: \(8i \times (4 + 3i)\)
- Denominator: \((4 - 3i)(4 + 3i)\)
Simplify the denominator using the difference of squares formula: \((a - bi)(a + bi) = a^2 + b^2\). Here, \(a=4\) and \(b=3\), so the denominator becomes \(4^2 + 3^2\).

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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Complex Number Standard Form

The standard form of a complex number is expressed as a + bi, where a and b are real numbers, and i is the imaginary unit with i² = -1. Writing complex numbers in this form separates the real and imaginary parts clearly.
추천 영상:
05:02
Multiplying Complex Numbers

Division of Complex Numbers

Dividing complex numbers involves multiplying the numerator and denominator by the conjugate of the denominator to eliminate the imaginary part in the denominator. This process simplifies the expression into a standard form.
추천 영상:
04:22
Dividing Complex Numbers

Complex Conjugate

The complex conjugate of a number a + bi is a - bi. Multiplying a complex number by its conjugate results in a real number, which helps in rationalizing denominators when dividing complex numbers.
추천 영상:
05:33
Complex Conjugates