/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 11 Evaluate each expression. Do not... [FREE SOLUTION] | 91Ó°ÊÓ

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Evaluate each expression. Do not use a calculator. $$8^{2 / 3}$$

Short Answer

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8^{2/3} = 4

Step by step solution

01

Understand the Expression

The expression to evaluate is \(8^{2/3}\). This means we need to find the number that when raised to the power of \(3\) gives \(8\), and then take that result and raise it to the power of \(2\). Essentially, we are dealing with a fractional exponent.
02

Evaluate the Denominator of the Exponent

The exponent \(2/3\) can be broken down into two parts. First, we deal with the denominator \(3\), which means to take the cube root of \(8\). Since \(2^3 = 8\), the cube root of \(8\) is \(2\).
03

Evaluate the Numerator of the Exponent

Now, take the result from Step 2, which is \(2\), and raise it to the power of the numerator, which is \(2\) in this case. So, calculate \(2^2 = 4\).
04

Combine the Results

The result of \(8^{2/3}\) is the answer from Step 3, which is \(4\). Therefore, \(8^{2/3} = 4\).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Cube Root
The cube root is a special mathematical operation that finds the number which, when multiplied by itself three times, gives the original number. Think of it as the opposite of cubing a number.
For example, to find the cube root of 8, you need to determine what number multiplied by itself three times equals 8. In this case, the answer is 2, because \(2 \times 2 \times 2 = 8\).
Understanding cube roots is essential when evaluating expressions with fractional exponents, as they often require taking roots as part of the operation. If you see an expression like \(x^{1/3}\), it signifies the cube root of \(x\).
  • The cube root of 27 is 3, because \(3^3 = 27\).
  • The cube root of 64 is 4, because \(4^3 = 64\).
Knowing how to determine cube roots mentally can greatly aid in solving problems without a calculator.
Exponentiation
Exponentiation is a mathematical operation involving two numbers, the base and the exponent. The operation \(b^n\) means multiplying the base \(b\) by itself \(n\) times.
This operation helps in expressing repeated multiplication concisely. For example, \(2^3 = 2 \times 2 \times 2 = 8\). With fractional exponents such as \(8^{2/3}\), you are dealing with roots and powers wrapped into one expression.
The exponentiation process for fractional exponents involves two steps:
  • Taking the root as indicated by the denominator.
  • Raising the result to the power indicated by the numerator.
This dual-step process helps simplify expressions to a more manageable form, as seen in the steps for solving \(8^{2/3}\), where the final result is 4.
Mathematical Expression Evaluation
Evaluating mathematical expressions is the process of performing operations in the correct sequence to find a single value. This involves following the established order of operations, often remembered through the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction).
In the context of the expression \(8^{2/3}\), our focus is on exponents, specifically fractional exponents.
To evaluate \(8^{2/3}\), start by understanding the fractional exponent:
  • The denominator (3) tells us to take the cube root of 8, resulting in 2.
  • The numerator (2) then indicates that we raise 2 to the power of 2, resulting in 4.
This is a systematic process where you break down complex expressions into simpler steps, making them easier to solve. Mastering this skill allows you to solve a variety of mathematical problems more efficiently.

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Most popular questions from this chapter

Solve each problem. To estimate the speed \(s\) at which a car was traveling at the time of an accident, a police officer drives a car like the one involved in the accident under conditions similar to those during which the accident took place and then skids to a stop. If the car is driven at 30 miles per hour, the speed \(s\) at the time of the accident is given by $$s=30 \sqrt{\frac{a}{p}}$$ where \(a\) is the length of the skid marks and \(p\) is the length of the marks in the police test. Find \(s\) if \(a=900\) feet and \(p=97\) feet.

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Solve each problem. Planetary Orbits The formula $$ f(x)=x^{1.5} $$ calculates the number of years it would take for a planet to orbit the sun if its average distance from the sun is \(x\) times farther than Earth. If there were a planet located 15 times farther from the sun than Earth, how many years would it take for the planet to orbit the sun?

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