Chapter 9: Problem 148
Explain how would you evaluate an expression with a mixed-number exponent. For example, what is \(8^{1 \frac{1}{3}} ?\) What is \(25^{2 \frac{1}{2}} ?\)
Short Answer
Expert verified
\(8^{1 \frac{1}{3}} = 16\); \(25^{2 \frac{1}{2}} = 3125\).
Step by step solution
01
Understanding Mixed-Number Exponents
A mixed-number exponent like \( 1 \frac{1}{3} \) represents the sum of an integer and a fraction. For \( 1 \frac{1}{3} \), it’s equivalent to \( 1 + \frac{1}{3} \). Therefore, \( 8^{1 \frac{1}{3}} \) can be rewritten as \( 8^{1 + \frac{1}{3}} \), which is the same as \( 8^1 \times 8^{\frac{1}{3}} \).
02
Simplifying Integer Exponent
First, simplify the integer exponent part. \( 8^1 \) is simply \( 8 \). So the expression becomes \( 8 \times 8^{\frac{1}{3}} \).
03
Evaluating the Fractional Exponent
The fractional exponent \( \frac{1}{3} \) indicates a cube root. Therefore, \( 8^{\frac{1}{3}} = \sqrt[3]{8} = 2 \). So the expression \( 8 \times 8^{\frac{1}{3}} \) becomes \( 8 \times 2 = 16 \).
04
Evaluating Second Expression
For \( 25^{2 \frac{1}{2}} \), rewrite it as \( 25^2 \times 25^{\frac{1}{2}} \). \( 25^2 = 625 \) and \( 25^{\frac{1}{2}} = \sqrt{25} = 5 \).
05
Final Calculation
Multiply the results from previous calculations to find the final value. \( 625 \times 5 = 3125 \). Thus, \( 25^{2 \frac{1}{2}} \) equals \( 3125 \).
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.
Mixed-Number Exponents
Working with mixed-number exponents might initially seem tricky, but they can be quite simple once you break them down. A mixed-number exponent combines an integer and a fraction. For instance, in the expression \( 8^{1 \frac{1}{3}} \), the exponent \( 1 \frac{1}{3} \) can be seen as \( 1 + \frac{1}{3} \).
To simplify this, you want to split the exponent into separate parts: the integer part (1) and the fractional part (\( \frac{1}{3} \)).
To simplify this, you want to split the exponent into separate parts: the integer part (1) and the fractional part (\( \frac{1}{3} \)).
- So, \( 8^{1 \frac{1}{3}} \) can be rewritten as \( 8^1 \times 8^{\frac{1}{3}} \).
- Then you solve \( 8^1 \) and \( 8^{\frac{1}{3}} \) separately.
Fractional Exponents
Fractional exponents represent roots. They tell us to take specific roots of a number rather than multiplying the base by itself multiple times.
When you see an exponent such as \( a^{\frac{1}{n}} \), it means you're finding the \( n \)-th root of \( a \).
When you see an exponent such as \( a^{\frac{1}{n}} \), it means you're finding the \( n \)-th root of \( a \).
- For example, \( 8^{\frac{1}{3}} \) means you're finding the cube root of 8, which is 2.
- Similarly, \( 25^{\frac{1}{2}} \) means you're finding the square root of 25, which is 5.
Cube Root
The cube root of a number is what we multiply by itself three times to get that number. It's denoted using the radical symbol with a little 3 above it, like this: \( \sqrt[3]{x} \).
Understanding cube roots is essential when dealing with cubic equations or simplifying expressions with fractional exponents of \( \frac{1}{3} \).
Understanding cube roots is essential when dealing with cubic equations or simplifying expressions with fractional exponents of \( \frac{1}{3} \).
- For instance, \( \sqrt[3]{8} = 2 \), because \( 2 \times 2 \times 2 = 8 \).
- Another example: \( \sqrt[3]{27} = 3 \), since \( 3 \times 3 \times 3 = 27 \).
Square Root
The square root function simplifies expressions by identifying a number that, when multiplied by itself, equals the original number. It's symbolized with the radical sign: \(\sqrt{x}\).
Square roots are easy to spot in fractional exponents like \( \frac{1}{2} \).
Square roots are easy to spot in fractional exponents like \( \frac{1}{2} \).
- \( \sqrt{25} = 5 \) because \( 5 \times 5 = 25 \).
- \( \sqrt{4} = 2 \) since \( 2 \times 2 = 4 \).