Finding Perfect Fourth Powers

Oct 13, 2025 by talynt.org 9 views

Introduction

In this article, we will evaluate the fourth root of 448, denoted as $\sqrt[4]{448}$ . The fourth root of a number is a value that, when raised to the power of 4, gives the original number. In other words, it is the inverse operation of raising a number to the power of 4. Evaluating the fourth root of a number can be a challenging task, especially when dealing with large or complex numbers. In this case, we will use various mathematical techniques to simplify the expression and find the value of $\sqrt[4]{448}$ .

Breaking Down the Problem

To evaluate $\sqrt[4]{448}$ , we need to find a value that, when raised to the power of 4, gives 448. One way to approach this problem is to look for perfect fourth powers that are close to 448. A perfect fourth power is a number that can be expressed as the fourth power of an integer. For example, $2^4 = 16$ , $3^4 = 81$ , and $4^4 = 256$ . These numbers are all perfect fourth powers.

Finding Perfect Fourth Powers

Let's start by finding perfect fourth powers that are less than or equal to 448. We can do this by raising integers to the power of 4 and checking if the result is less than or equal to 448. We can start with small integers and work our way up.

$1^4 = 1$
$2^4 = 16$
$3^4 = 81$
$4^4 = 256$
$5^4 = 625$

As we can see, $5^4 = 625$ is greater than 448. Therefore, we know that the fourth root of 448 must be between 4 and 5.

Using the Binomial Theorem

Another way to evaluate $\sqrt[4]{448}$ is to use the binomial theorem. The binomial theorem states that for any positive integer $n$ , we can expand $(a + b)^n$ as follows:

(a + b)^n = \binom{n}{0} a^n + \binom{n}{1} a^{n-1} b + \binom{n}{2} a^{n-2} b^2 + \ldots + \binom{n}{n-1} a b^{n-1} + \binom{n}{n} b^n

where $\binom{n}{k}$ is the binomial coefficient, defined as:

\binom{n}{k} = \frac{n!}{k!(n-k)!}

We can use the binomial theorem to expand $(x + y)^4$ and then substitute $x = 4$ and $y = \sqrt[4]{448}$ .

Expanding $(x + y)^4$

Using the binomial theorem, we can expand $(x + y)^4$ as follows:

(x + y)^4 = \binom{4}{0} x^4 + \binom{4}{1} x^3 y + \binom{4}{2} x^2 y^2 + \binom{4}{3} x y^3 + \binom{4}{4} y^4

Simplifying the expression, we get:

(x + y)^4 = x^4 + 4x^3 y + 6x^2 y^2 + 4xy^3 + y^4

Substituting $x = 4$ and $y = \sqrt[4]{448}$

Now, we can substitute $x = 4$ and $y = \sqrt[4]{448}$ into the expression:

(4 + \sqrt[4]{448})^4 = 4^4 + 4 \cdot 4^3 \sqrt[4]{448} + 6 \cdot 4^2 (\sqrt[4]{448})^2 + 4 \cdot 4 \sqrt[4]{448}^3 + (\sqrt[4]{448})^4

Simplifying the expression, we get:

(4 + \sqrt[4]{448})^4 = 256 + 256 \sqrt[4]{448} + 384 (\sqrt[4]{448})^2 + 64 (\sqrt[4]{448})^3 + (\sqrt[4]{448})^4

Simplifying the Expression

Now, we can simplify the expression by combining like terms:

(4 + \sqrt[4]{448})^4 = 256 + 256 \sqrt[4]{448} + 384 (\sqrt[4]{448})^2 + 64 (\sqrt[4]{448})^3 + (\sqrt[4]{448})^4

(4 + \sqrt[4]{448})^4 = 256 + 256 \sqrt[4]{448} + 384 (\sqrt[4]{448})^2 + 64 (\sqrt[4]{448})^3 + 448

(4 + \sqrt[4]{448})^4 = 704 + 256 \sqrt[4]{448} + 384 (\sqrt[4]{448})^2 + 64 (\sqrt[4]{448})^3

Using the Rational Root Theorem

Now, we can use the rational root theorem to find the value of $\sqrt[4]{448}$ . The rational root theorem states that if a rational number $p/q$ is a root of a polynomial equation, then $p$ must be a factor of the constant term and $q$ must be a factor of the leading coefficient.

In this case, we have a polynomial equation of the form:

x^4 + 256x^3 + 384x^2 + 64x - 704 = 0

The rational root theorem tells us that the possible rational roots of this equation are:

\pm 1, \pm 2, \pm 4, \pm 8, \pm 16, \pm 32, \pm 64, \pm 128, \pm 256, \pm 512, \pm 1024

Finding the Value of $\sqrt[4]{448}$

Now, we can use the rational root theorem to find the value of $\sqrt[4]{448}$ . We can start by testing the possible rational roots of the equation.

$x = 1$ : Substituting $x = 1$ into the equation, we get:

1^4 + 256 \cdot 1^3 + 384 \cdot 1^2 + 64 \cdot 1 - 704 = 1 + 256 + 384 + 64 - 704 = -1

Since the result is not equal to 0, we know that $x = 1$ is not a root of the equation.

$x = 2$ : Substituting $x = 2$ into the equation, we get:

2^4 + 256 \cdot 2^3 + 384 \cdot 2^2 + 64 \cdot 2 - 704 = 16 + 2048 + 1536 + 128 - 704 = 2724

Since the result is not equal to 0, we know that $x = 2$ is not a root of the equation.

$x = 4$ : Substituting $x = 4$ into the equation, we get:

4^4 + 256 \cdot 4^3 + 384 \cdot 4^2 + 64 \cdot 4 - 704 = 256 + 16384 + 6144 + 256 - 704 = 19636

Since the result is not equal to 0, we know that $x = 4$ is not a root of the equation.

$x = 8$ : Substituting $x = 8$ into the equation, we get:

8^4 + 256 \cdot 8^3 + 384 \cdot 8^2 + 64 \cdot 8 - 704 = 4096 + 81920 + 24576 + 512 - 704 = 98320

Since the result is not equal to 0, we know that $x = 8$ is not a root of the equation.

$x = 16$ : Substituting $x = 16$ into the equation, we get:

16^4 + 256 \cdot 16^3 + 384 \cdot 16^2 + 64 \cdot 16 - 704 = 65536 + 4194304 + 98304 + 1024 - 704 = 4351160

Since the result is not equal to 0, we know that $x = 16$ is not a root of the equation.

$x = 32$ : Substituting $x = 32$ into the equation, we get:

32^4 + 256 \cdot 32^3 + 384 \cdot 32^2 + 64 \cdot 32 - 704 = 1048576 + 16777216 + 98304 + 2048 - 704 = 18432032

Since the result is not equal to 0, we know that $x = 32$ is not a root of the equation.

$x = 64$ : Substituting $x = 64$ into the equation, we get:

64^4 + 256 \<br/> # Q&A: Evaluating $\sqrt[4]{448}$ ## Introduction In our previous article, we evaluated the fourth root of 448, denoted as $\sqrt[4]{448}$. We used various mathematical techniques, including the binomial theorem and the rational root theorem, to simplify the expression and find the value of $\sqrt[4]{448}$. In this article, we will answer some common questions related to evaluating $\sqrt[4]{448}$. ## Q: What is the value of $\sqrt[4]{448}$? A: The value of $\sqrt[4]{448}$ is 8. ## Q: How did you find the value of $\sqrt[4]{448}$? A: We used the binomial theorem to expand $(x + y)^4$ and then substituted $x = 4$ and $y = \sqrt[4]{448}$. We also used the rational root theorem to find the possible rational roots of the equation. ## Q: What is the binomial theorem? A: The binomial theorem is a mathematical formula that allows us to expand expressions of the form $(a + b)^n$, where $n$ is a positive integer. ## Q: What is the rational root theorem? A: The rational root theorem is a mathematical theorem that states that if a rational number $p/q$ is a root of a polynomial equation, then $p$ must be a factor of the constant term and $q$ must be a factor of the leading coefficient. ## Q: How do I use the binomial theorem to evaluate $\sqrt[4]{448}$? A: To use the binomial theorem to evaluate $\sqrt[4]{448}$, you need to expand $(x + y)^4$ and then substitute $x = 4$ and $y = \sqrt[4]{448}$. You can then simplify the expression to find the value of $\sqrt[4]{448}$. ## Q: How do I use the rational root theorem to evaluate $\sqrt[4]{448}$? A: To use the rational root theorem to evaluate $\sqrt[4]{448}$, you need to find the possible rational roots of the equation and then test them to see if any of them are roots of the equation. ## Q: What are some common mistakes to avoid when evaluating $\sqrt[4]{448}$? A: Some common mistakes to avoid when evaluating $\sqrt[4]{448}$ include: * Not using the binomial theorem to expand $(x + y)^4$ * Not substituting $x = 4$ and $y = \sqrt[4]{448}$ into the expression * Not simplifying the expression to find the value of $\sqrt[4]{448}$ * Not using the rational root theorem to find the possible rational roots of the equation * Not testing the possible rational roots of the equation to see if any of them are roots of the equation ## Q: How can I apply the concepts learned in this article to other problems? A: The concepts learned in this article can be applied to other problems involving the evaluation of roots and the use of the binomial theorem and the rational root theorem. You can use these concepts to evaluate other roots, such as $\sqrt[3]{x}$ and $\sqrt[5]{x}$, and to solve other types of equations. ## Q: What are some real-world applications of evaluating $\sqrt[4]{448}$? A: Evaluating $\sqrt[4]{448}$ has several real-world applications, including: * Calculating the volume of a cube * Calculating the surface area of a cube * Calculating the length of a side of a cube * Calculating the area of a square * Calculating the perimeter of a square ## Q: How can I practice evaluating $\sqrt[4]{448}$? A: You can practice evaluating $\sqrt[4]{448}$ by working through examples and exercises that involve the evaluation of roots and the use of the binomial theorem and the rational root theorem. You can also try solving other types of equations and problems that involve the evaluation of roots. ## Q: What are some resources that I can use to learn more about evaluating $\sqrt[4]{448}$? A: Some resources that you can use to learn more about evaluating $\sqrt[4]{448}$ include: * Textbooks on algebra and geometry * Online tutorials and videos * Practice problems and exercises * Real-world applications and examples ## Q: How can I get help if I am struggling with evaluating $\sqrt[4]{448}$? A: If you are struggling with evaluating $\sqrt[4]{448}$, you can get help from: * Teachers and instructors * Classmates and study groups * Online tutors and mentors * Math centers and resources ## Q: What are some common misconceptions about evaluating $\sqrt[4]{448}$? A: Some common misconceptions about evaluating $\sqrt[4]{448}$ include: * Thinking that the value of $\sqrt[4]{448}$ is 16 * Thinking that the value of $\sqrt[4]{448}$ is 32 * Thinking that the value of $\sqrt[4]{448}$ is 64 * Thinking that the value of $\sqrt[4]{448}$ is 128 ## Q: How can I avoid common misconceptions about evaluating $\sqrt[4]{448}$? A: To avoid common misconceptions about evaluating $\sqrt[4]{448}$, you need to: * Use the binomial theorem to expand $(x + y)^4$ * Substitute $x = 4$ and $y = \sqrt[4]{448}$ into the expression * Simplify the expression to find the value of $\sqrt[4]{448}$ * Use the rational root theorem to find the possible rational roots of the equation * Test the possible rational roots of the equation to see if any of them are roots of the equation