Chapter 1: Problem 74
Simplify the fractional expression. (Expressions like these arise in calculus.) $$\sqrt{1+\left(x^{3}-\frac{1}{4 x^{3}}\right)^{2}}$$
Short Answer
Expert verified
The expression simplifies to \( x^3 + \frac{1}{4x^3} \).
Step by step solution
01
Identify the Expression
The expression given is \( \sqrt{1 + \left(x^3 - \frac{1}{4x^3}\right)^2} \). Our goal is to simplify this expression.
02
Expand the Squared Term
The part inside the square root \( \left(x^3 - \frac{1}{4x^3}\right)^2 \) can be expanded using the identity \((a-b)^2 = a^2 - 2ab + b^2\). Let \( a = x^3 \) and \( b = \frac{1}{4x^3} \).
03
Compute \( a^2 \) and \( b^2 \)
Calculate \( a^2 = (x^3)^2 = x^6 \) and \( b^2 = \left(\frac{1}{4x^3}\right)^2 = \frac{1}{16x^6} \).
04
Compute \( 2ab \)
Calculate \( 2ab = 2 \times x^3 \times \frac{1}{4x^3} = \frac{1}{2} \).
05
Formulate the Expanded Expression
Substitute into the expanded form: \( (x^3 - \frac{1}{4x^3})^2 = x^6 - \frac{1}{2} + \frac{1}{16x^6} \).
06
Substitute Back Into the Entire Expression
Now substitute this back into the original expression: \( \sqrt{1 + x^6 - \frac{1}{2} + \frac{1}{16x^6}} \).
07
Simplify the Expression Inside the Square Root
Combine the terms inside the square root: \( \sqrt{1 + x^6 - \frac{1}{2} + \frac{1}{16x^6}} = \sqrt{x^6 + \frac{1}{2} + \frac{1}{16x^6}} \).
08
Identify Perfect Square Trinomial
Notice that \( x^6 + \frac{1}{2} + \frac{1}{16x^6} \) is structured as a perfect square. It can be expressed as \( (x^3 + \frac{1}{4x^3})^2 \).
09
Simplify the Square Root
The expression simplifies further as: \( \sqrt{(x^3 + \frac{1}{4x^3})^2} = x^3 + \frac{1}{4x^3} \).
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.
Perfect Square Trinomial
In mathematics, a perfect square trinomial is an expression that can be expressed as the square of a binomial. The general form is: \((a-b)^2 = a^2 - 2ab + b^2\). Understanding this concept is crucial when simplifying expressions, especially when they appear under a radical.
The given expression involves a perfect square trinomial: \(x^6 + \frac{1}{2} + \frac{1}{16x^6}\). At first, this might not look like a perfect square. However, by recognizing the pattern \((a+b)^2\) and rearranging the terms, you see it leads to \((x^3 + \frac{1}{4x^3})^2\).
The given expression involves a perfect square trinomial: \(x^6 + \frac{1}{2} + \frac{1}{16x^6}\). At first, this might not look like a perfect square. However, by recognizing the pattern \((a+b)^2\) and rearranging the terms, you see it leads to \((x^3 + \frac{1}{4x^3})^2\).
- Identify the coefficients: set \(a = x^3\) and \(b = \frac{1}{4x^3}\).
- Verify the structure: compute \(a^2 = x^6\) and \(b^2 = \frac{1}{16x^6}\).
- Check the middle term: ensure \(-2ab = \frac{1}{2}\) matches the expression.
Radical Expressions
Radical expressions are mathematical expressions that contain a square root, cube root, or higher-order roots. Simplifying these expressions often involves factoring to reveal perfect squares that can simplify the radical part.
In our given problem, the radical \(\sqrt{1 + (x^3 - \frac{1}{4x^3})^2}\) aims to simplify by exposing a perfect square trinomial within. Once identified, the square root simplifies neatly.
In our given problem, the radical \(\sqrt{1 + (x^3 - \frac{1}{4x^3})^2}\) aims to simplify by exposing a perfect square trinomial within. Once identified, the square root simplifies neatly.
- Identify terms under the radical first.
- Factor or expand the expression: expose terms like \((a+b)^2\) that simplify directly under the square root.
- Simplify: convert \(\sqrt{(a+b)^2}\) into \(|a+b|\), which here resolves straightforwardly as \(a + b\).
Expanding Binomials
Expanding binomials refers to using algebraic identities to multiply expressions like \((a-b)^2\). Knowing how to expand correctly is essential when breaking down expressions for further simplification, such as preparing to simplify a radical.
The exercise started with finding expansion for the squared term \((x^3 - \frac{1}{4x^3})^2\). Using the formula \((a-b)^2 = a^2 - 2ab + b^2\), we meticulously expanded the terms:
The exercise started with finding expansion for the squared term \((x^3 - \frac{1}{4x^3})^2\). Using the formula \((a-b)^2 = a^2 - 2ab + b^2\), we meticulously expanded the terms:
- Square each term: \(a^2 = x^6\) and \(b^2 = \frac{1}{16x^6}\).
- Multiply the terms for middle coefficient: \(2ab = \frac{1}{2}\).
- Combine them back: the result is the simplified term inside the radical.