Chapter 3: Problem 28
In Exercises 28–35, find the indicated roots without using a calculator. the cube root of \(-216\)
Short Answer
Expert verified
The cube root of \(-216\) is \-6\.
Step by step solution
01
- Understand the problem
The problem requires finding the cube root of \(-216\). A cube root asks what number, when multiplied by itself three times, results in \(-216\).
02
- Consider properties of cube roots
Recall that the cube root of a negative number is also negative. This is because a negative number multiplied by itself three times remains negative.
03
- Break down the number
Consider the absolute value \(216\) and find its prime factorization to help determine its cube root. \(216 = 6 \times 6 \times 6 = 6^3\)
04
- Apply the cube root
Since \(216 = 6^3\), the cube root of \216\ is \6\. Therefore, the cube root of \(-216\) is \-6\ because \(-6 \times -6 \times -6 = -216\).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Understanding Negative Numbers
Negative numbers are numbers less than zero and are represented with a minus sign (e.g., -1, -2, -3). They play a crucial role in mathematics, especially when working with roots and exponents. Here are some important points to remember about negative numbers:
- When you multiply an odd number of negative numbers, the result is negative (e.g., ewlineewline -2 × -2 × -2 = -8).
- When you multiply an even number of negative numbers, the result is positive (e.g., ewlineewline -2 × -2 = 4).
Prime Factorization
Prime factorization involves breaking down a number into its prime number factors. Prime numbers are numbers greater than 1 that have no divisors other than 1 and themselves (e.g., 2, 3, 5, 7). To find the prime factorization of a number, you repeatedly divide by the smallest prime number until you reach 1.
Here's how to find the prime factorization of 216:
Here's how to find the prime factorization of 216:
- 216 can be divided by 2: ewlineewline 216 ÷ 2 = 108.
- 108 can be divided by 2: ewlineewline 108 ÷ 2 = 54.
- 54 can be divided by 2: ewlineewline 54 ÷ 2 = 27.
- 27 can be divided by 3: ewlineewline 27 ÷ 3 = 9.
- 9 can be divided by 3: ewlineewline 9 ÷ 3 = 3.
- Finally, 3 can be divided by 3:ewline ewline3 ÷ 3 = 1.
Properties of Exponents
Exponents are used to represent repeated multiplication of a number by itself. In the expression ewlineewline 6^3, 6 is the base and 3 is the exponent, which means 6 multiplied by itself three times (6 × 6 × 6). Here are some fundamental properties of exponents to keep in mind:
- Product of powers: When we multiply two powers with the same base, we add the exponents:ewlineewline a^m * a^n = a^(m+n).
- Power of a power: When we take a power to another power, we multiply the exponents:ewlineewline (a^m)^n = a^(m*n).
- Power of a product: When we take the power of a product, we apply the exponent to each factor inside the parentheses:ewlineewline (ab)^n = a^n * b^n.
- Negative exponents: A negative exponent represents the reciprocal of the base raised to the positive exponent:ewlineewline a^(-n) = 1/a^n.