Chapter 3: Problem 107
Find \(f^{\prime}(x)\) for each function. $$ f(x)=5 x^{3}-x+1 $$
Short Answer
Expert verified
\( f'(x) = 15x^2 - 1 \)
Step by step solution
01
Identify the Function
The given function is \( f(x) = 5x^3 - x + 1 \). This is a polynomial function of degree 3, where each term can be differentiated separately.
02
Apply the Power Rule to Each Term
The power rule for differentiation states that \( \frac{d}{dx} [x^n] = nx^{n-1} \). We will apply this rule to each term of the function separately. The first term is \( 5x^3 \), the second term is \( -x \), and the last term is \( +1 \).
03
Differentiate the First Term
Differentiate \( 5x^3 \) using the power rule: \( \frac{d}{dx} [5x^3] = 3 \cdot 5x^{3-1} = 15x^2 \).
04
Differentiate the Second Term
Differentiate \( -x \) using the power rule: \( \frac{d}{dx} [-x] = -1 \cdot x^{1-1} = -1 \).
05
Differentiate the Constant Term
The derivative of a constant is 0. Therefore, \( \frac{d}{dx} [1] = 0 \).
06
Combine the Derivatives
Combine the derivatives of each term to find \( f'(x) \): \( f'(x) = 15x^2 - 1 + 0 \). Hence, \( f'(x) = 15x^2 - 1 \).
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.
polynomial function
A polynomial function is an expression made up of variables and constants combined using addition, subtraction, and multiplication. In general, a polynomial can be written as:
- The sum of terms, each consisting of a constant (called a coefficient) multiplied by a whole number power of a variable.
- For instance, the expression \( f(x) = 5x^3 - x + 1 \) is a polynomial function.
- Here, the coefficients are 5, -1, and 1, while the variable is \( x \).
- The degree of the polynomial is determined by the term with the highest exponent, which in this case is 3 (from \( 5x^3 \)).
power rule
The power rule is a fundamental tool in differentiation. It allows us to easily find the derivative of terms that are powers of a variable.To apply the power rule:
- If you have a term \( x^n \), the derivative is \( nx^{n-1} \).
- This means you multiply by the power and then subtract one from the exponent.
- For \( 5x^3 \), differentiate to get \( 15x^2 \), since \( 3 \times 5 = 15 \) and \( 3-1 = 2 \).
- For \( -x \), rethink of it as \( -1x^1 \). Using the power rule, it becomes \( -1 \cdot 1x^{1-1} = -1 \).
- Constants, like \( +1 \), have a derivative of 0 because constants do not change as \( x \) changes.
derivative
A derivative is a concept that measures how a function changes as its input changes. Think of it as the function's sensitivity to change.The derivative, denoted as \( f'(x) \), tells you the rate of change or slope of a function at any given point.
- For instance, the derivative of \( f(x) = 5x^3 - x + 1 \) after applying the power rule is \( f'(x) = 15x^2 - 1 \).
- Here, \( 15x^2 \) represents how the cubic term influences the rate of change, while \(-1\) reflects the linear component's effect.
- They help in understanding the behavior of systems over time.
- From predicting how stock prices change to figuring out the speed of an object.