Chapter 1: Problem 38
Evaluate each expression without using a calculator. $$ 16^{-3 / 4} $$
Short Answer
Expert verified
The value of \(16^{-3/4}\) is \(\frac{1}{8}\).
Step by step solution
01
Understand Exponent Notation
The expression \(16^{-\frac{3}{4}}\) is composed of a base, 16, and an exponent, -3/4. A negative exponent indicates that the base, 16, should be taken as the reciprocal raised to the positive exponent, \/\frac{3}{4}.
02
Rewrite with Positive Exponent
Convert the expression with the negative exponent to a positive one. \[16^{-\frac{3}{4}} = \frac{1}{16^{\frac{3}{4}}}\]
03
Simplify the Exponentiation
Now, find \(16^{\frac{3}{4}}\). Start by understanding that \(16^{\frac{3}{4}}\) means taking the 4th root of 16 first and then cubing the result. \[16^{\frac{1}{4}} = \sqrt[4]{16} = 2\] Thus, \(16^{\frac{3}{4}}\) becomes \(2^3\).
04
Evaluate the Power
Calculate \(2^3\) which is the cube of 2. \[2^3 = 2 \times 2 \times 2 = 8\]
05
Determine the Reciprocal
Substitute \(16^{\frac{3}{4}}\) back into the reciprocal expression to get the final evaluation. \[\frac{1}{16^{\frac{3}{4}}} = \frac{1}{8}\].
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
When we see a negative exponent, it means we are looking at the reciprocal of the base raised to the opposite positive exponent. This might sound a bit confusing, so let's clarify with examples:
- For example, if you see \(a^{-n}\), it should be interpreted as \(\frac{1}{a^n}\).
- This concept helps in transforming complex exponential problems into simpler fractions.
Fractional Exponents
Fractional exponents indicate both roots and powers. For example, the expression \(a^{m/n}\) means take the \(n\)-th root of \(a\) and then raise the result to the \(m\)-th power.
- Think of it like doing two operations. First, extract the root, and next, raise it to the given power.
- In our example of \(16^{-\frac{3}{4}}\), once simplified, it involves finding the fourth root of 16, which is 2.
Simplifying Radicals
Simplifying radicals involves breaking down expressions to their simplest radical form. Consider the expression \(\sqrt[4]{16}\). Here's how you approach it:
- Look for a number that can multiply itself to equal the base inside the radical, in this case, four times over, since it's a fourth root.
- For \(16\), the fourth root is 2 because \(2 \times 2 \times 2 \times 2 = 16\).