Skip to main content
Ch. R - Review of Basic Concepts
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
1장, 문제 15

Write each root using exponents and evaluate. ∛-125

검증된 단계별 안내
1
Recognize that the cube root of a number can be expressed using exponents as raising the number to the power of \( \frac{1}{3} \). So, \( \sqrt[3]{-125} = (-125)^{\frac{1}{3}} \).
Recall that \( -125 \) can be written as \( -(5^3) \) because \( 5^3 = 125 \). So rewrite the expression as \( (-(5^3))^{\frac{1}{3}} \).
Use the property of exponents \( (a^m)^n = a^{m \cdot n} \) to simplify the expression: \( (-(5^3))^{\frac{1}{3}} = - (5^{3 \cdot \frac{1}{3}}) \).
Simplify the exponent multiplication \( 3 \cdot \frac{1}{3} = 1 \), so the expression becomes \( -5^1 \).
Therefore, the cube root of \( -125 \) simplifies to \( -5 \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m
도움이 되었나요?

주요 개념

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

Cube Roots and Radicals

The cube root of a number is a value that, when multiplied by itself three times, gives the original number. It is denoted by the radical symbol with an index of 3, such as ∛x. For example, ∛-125 asks for a number which cubed equals -125.
추천 영상:
가이드 코스
05:20
Expanding Radicals

Expressing Roots Using Exponents

Roots can be rewritten as fractional exponents, where the nth root of a number x is expressed as x^(1/n). For the cube root, ∛x is equivalent to x^(1/3). This allows the use of exponent rules to simplify and evaluate roots.
추천 영상:
가이드 코스
04:06
Rational Exponents

Evaluating Negative Bases with Odd Roots

When taking an odd root (like a cube root) of a negative number, the result is also negative because an odd number of negative factors multiplied together remains negative. Thus, ∛-125 equals -5, since (-5)^3 = -125.
추천 영상:
05:02
Square Roots of Negative Numbers