Chapter 4: Problem 13
Evaluate each expression. Do not use a calculator. $$16^{-3 / 4}$$
Short Answer
Expert verified
The value of \( 16^{-3/4} \) is \( \frac{1}{8} \).
Step by step solution
01
Identify the Base and Exponent
The expression given is \( 16^{-3/4} \). Here, 16 is the base, and \(-3/4\) is the exponent. The negative exponent indicates that the expression is the reciprocal of the base raised to a positive exponent.
02
Rewriting the Negative Exponent
Rewrite the expression using the negative exponent rule: \( a^{-n} = \frac{1}{a^n} \). Thus, \( 16^{-3/4} = \frac{1}{16^{3/4}} \).
03
Simplify the Expression with Positive Exponent
To simplify \( 16^{3/4} \), use the property that \( a^{m/n} = \sqrt[n]{a^m} \). Here, we have \( 16^{3/4} = (16)^{1/4}^3 \).
04
Evaluate the Fourth Root
Evaluate \( 16^{1/4} \). The fourth root of 16 is the number which raised to the power of 4 equals 16. Since \( 2^4 = 16 \), \( 16^{1/4} = 2 \).
05
Raise to the Power of 3
Now, raise the result from Step 4 to the power of 3: \( 2^3 = 8 \).
06
Determine the Reciprocal
From Step 2, since our exponent is originally negative, take the reciprocal of the result we found: \( \frac{1}{8} \).
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.
Negative Exponents
In mathematics, we often encounter expressions with negative exponents. A negative exponent signifies that the base should be inverted or turned into its reciprocal, which means flipping it to the bottom of a fraction if it is initially on the top, and vice versa. For instance:
- If you have an expression such as \( a^{-n} \), it can be rewritten as \( \frac{1}{a^n} \).
- This principle helps simplify expressions by allowing us to switch between negative and positive exponents, which often makes calculations more manageable.
Rational Exponents
Rational exponents are a type of exponent that involve fractions. Specifically, they describe roots along with the usual power of a number and provide a way to express radicals more compactly. Here's what you need to know:
- When you see an expression like \( a^{m/n} \), it implies two operations. The base \( a \) is first raised to the power of \( m \), and then you take the \( n^{th} \) root of that result, or vice versa.
- This is interpreted as \( \sqrt[n]{a^m} \). You could also see it as doing the nth root first, then raising it to the m-th power.
Roots
Roots are fundamental operations in mathematics, especially when handling rational exponents. They essentially reverse the process of exponentiation.
- The nth root of a number \( a \), written as \( \sqrt[n]{a} \), is the value that, when raised to the nth power, equals \( a \).
- For example, the square root (\( \sqrt{} \)) is the most common root operation, but other roots like the cube root \( \sqrt[3]{} \) and the fourth root \( \sqrt[4]{} \) are just as important in various applications.