Skip to main content
Ch. 5 - Complex Numbers, Polar Coordinates and Parametric Equations
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601당신이 사용하는 게 아니라요?교과서 변경
5장, 문제 39

In Exercises 37–52, perform the indicated operations and write the result in standard form. ___ ___ 5√−16 + 3√−81

검증된 단계별 안내
1
Recognize that the expressions involve square roots of negative numbers, which means we are dealing with imaginary numbers. Recall that \(\sqrt{-a} = \sqrt{a} \times i\), where \(i\) is the imaginary unit with the property \(i^2 = -1\).
Rewrite each term by separating the negative sign inside the square root: \(5\sqrt{-16} = 5 \times \sqrt{16} \times i\) and \(3\sqrt{-81} = 3 \times \sqrt{81} \times i\).
Calculate the square roots of the positive numbers: \(\sqrt{16} = 4\) and \(\sqrt{81} = 9\), so the expressions become \(5 \times 4 \times i\) and \(3 \times 9 \times i\) respectively.
Multiply the coefficients: \(5 \times 4 = 20\) and \(3 \times 9 = 27\), so the terms are \$20i\( and \)27i$.
Add the two imaginary terms together: \(20i + 27i = (20 + 27)i\), which simplifies to \$47i$. This is the result in standard form, where the real part is 0 and the imaginary part is \(47\).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m
도움이 되었나요?

주요 개념

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

Imaginary Numbers and Complex Numbers

Imaginary numbers arise from the square roots of negative numbers, defined using the imaginary unit i, where i² = -1. Complex numbers combine real and imaginary parts in the form a + bi, allowing operations involving roots of negative numbers to be expressed in standard form.
추천 영상:
3:31
Introduction to Complex Numbers

Simplifying Square Roots of Negative Numbers

To simplify the square root of a negative number, separate it into the square root of the positive part times the square root of -1. For example, √-16 = √16 × √-1 = 4i. This process converts the expression into a form involving imaginary units, facilitating further arithmetic.
추천 영상:
2:20
Imaginary Roots with the Square Root Property

Addition of Complex Numbers and Standard Form

Adding complex numbers involves combining their real parts and imaginary parts separately. The standard form of a complex number is a + bi, where a and b are real numbers. Writing results in this form ensures clarity and consistency in representing complex expressions.
추천 영상:
04:47
Complex Numbers In Polar Form