Chapter 4: Problem 12
find \(\frac{d}{d x} f(x)\) $$ f(x)=x^{2 / 5} $$
Short Answer
Expert verified
The derivative is \( \frac{2}{5}x^{-3/5} \).
Step by step solution
01
Identify the Function and Its Form
The function given is \( f(x) = x^{2/5} \). This is a power function where the base is \( x \) and the exponent is \( \frac{2}{5} \).
02
Recall the Power Rule for Derivatives
The power rule for differentiation states that if \( f(x) = x^n \), then the derivative \( \frac{d}{dx}f(x) = nx^{n-1} \). This means you need to multiply the variable \( x \) by the exponent and then subtract one from the exponent.
03
Apply the Power Rule
Applying the power rule to \( f(x) = x^{2/5} \), you multiply \( x \) by the exponent \( \frac{2}{5} \). Then, subtract 1 from the exponent, which gives the new exponent as \( \frac{2}{5} - 1 = -\frac{3}{5} \).
04
Calculate the Derivative
The derivative is calculated as follows:\[ \frac{d}{dx}f(x) = \frac{2}{5}x^{-3/5} \]This means the derivative of \( f(x) = x^{2/5} \) is \( \frac{2}{5}x^{-3/5} \).
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.
Power Rule for Derivatives
The power rule for derivatives is a fundamental concept in calculus that simplifies finding the derivative of power functions. Power functions are functions where a variable, typically noted as \( x \), is raised to a constant exponent. The power rule states that if you have a function \( f(x) = x^n \), its derivative, denoted as \( \frac{d}{dx}f(x) \), is \( nx^{n-1} \). This means:
- Multiply the variable's exponent by the coefficient (often implicit as 1 when it's just \( x^n \)).
- Subtract one from the exponent.
Differentiation Methods
Differentiation is the process of finding a derivative, which measures how a function changes as its input changes. One popular method is the power rule, as discussed, but there are other techniques as well, including:
- Product Rule: Used when differentiating products of two functions. If \( u(x) \) and \( v(x) \) are functions, the derivative is \((uw)' = u'v + uv'\).
- Quotient Rule: Useful for functions that are ratios of two functions. If your function is \( f(x) = \frac{u(x)}{v(x)} \), the derivative is \( \, \frac{u'v - uv'}{v^2} \, \).
- Chain Rule: Perfect for composite functions, where one function is nested inside another. If \( y = g(f(x)) \), then the derivative is \( \frac{dy}{dx} = g'(f(x)) \cdot f'(x) \).
Mathematical Functions
Mathematical functions are essential building blocks in calculus, and understanding them is critical for differentiating functions accurately. Functions can take many forms, such as:
- Polynomial Functions: These are sums of constants times variables raised to non-negative integer powers, like \( f(x) = 3x^3 + 2x^2 + x - 5 \).
- Rational Functions: These are ratios of polynomial functions, for example, \( g(x) = \frac{2x^2 + 3}{x - 1} \).
- Exponential Functions: These involve the base of a constant raised to the power of a variable, like \( h(x) = 2^x \).
- Logarithmic Functions: These functions are the inverse of exponential functions, such as \( \, \log_b(x) \, \).