Solving (s-t)(x) A Comprehensive Guide To Function Subtraction

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#h1 Suppose that the functions s and t are defined for all real numbers x as follows:

s(x)=x3t(x)=3x2\begin{array}{l} s(x)=x^3 \\ t(x)=3 x^2 \end{array}

Write the expressions for $(s-t)(x)$. This article delves into the realm of function operations, specifically focusing on the difference of two functions. We'll break down the concept of $(s-t)(x)$, providing a step-by-step explanation to ensure clarity and comprehension. Understanding function operations is crucial in various mathematical contexts, from calculus to real analysis. This article serves as a comprehensive guide, equipping you with the knowledge to confidently tackle problems involving the difference of functions.

Decoding Function Operations: (s-t)(x)

#h2 Function operations form the bedrock of advanced mathematical concepts. Understanding how functions interact through addition, subtraction, multiplication, and division unlocks a deeper understanding of mathematical relationships. In this section, we will explore the concept of function subtraction, focusing on the specific case of $(s-t)(x)$. Function subtraction, denoted as $(f-g)(x)$, is a fundamental operation where the output of one function is subtracted from the output of another function for a given input $x$. Mathematically, it's defined as $(f-g)(x) = f(x) - g(x)$.

To truly grasp the essence of function subtraction, let's delve into a detailed explanation. The expression $(s-t)(x)$ represents a new function formed by subtracting the function $t(x)$ from the function $s(x)$. For any given input $x$, we first evaluate both $s(x)$ and $t(x)$ individually. Then, we subtract the value of $t(x)$ from the value of $s(x)$. This resulting value becomes the output of the new function $(s-t)(x)$ for that specific input $x$. This process underscores that function subtraction is not merely a symbolic manipulation; it's a concrete operation that yields a new function with its own unique behavior and characteristics. The domain of the resulting function $(s-t)(x)$ is the intersection of the domains of $s(x)$ and $t(x)$, ensuring that the subtraction is defined for all valid inputs. By mastering function subtraction, you gain a powerful tool for manipulating and analyzing mathematical relationships, paving the way for success in advanced mathematical studies.

Step-by-Step Solution for (s-t)(x)

#h2 To determine the expression for $(s-t)(x)$, we apply the definition of function subtraction. Given the functions $s(x) = x^3$ and $t(x) = 3x^2$, we follow a systematic approach to arrive at the solution. The key is to meticulously substitute the given functions into the expression $(s-t)(x) = s(x) - t(x)$, ensuring that each step is logically sound and mathematically accurate.

The first step is to substitute the expressions for $s(x)$ and $t(x)$ into the equation. We replace $s(x)$ with $x^3$ and $t(x)$ with $3x^2$. This substitution transforms the expression $(s-t)(x)$ into $x^3 - 3x^2$. This resulting expression, $x^3 - 3x^2$, is the simplified form of $(s-t)(x)$. It represents a new function that describes the difference between the cubic function $s(x)$ and the quadratic function $t(x)$. The expression highlights the interplay between the two original functions, showcasing how their individual behaviors combine to create a distinct mathematical entity. The process of substitution underscores the power of algebraic manipulation in revealing the underlying structure of function operations. By carefully applying this technique, we can effectively determine the expressions for more complex combinations of functions, expanding our toolkit for mathematical analysis and problem-solving. Understanding the step-by-step solution not only provides the answer but also reinforces the underlying principles of function subtraction, fostering a deeper comprehension of mathematical concepts.

The Result: (s-t)(x) = x³ - 3x²

#h2 The solution to the problem, $(s-t)(x) = x^3 - 3x^2$, represents a new function derived from the subtraction of $t(x)$ from $s(x)$. This expression succinctly captures the relationship between the two original functions and provides a powerful tool for further analysis. The result, a cubic polynomial, demonstrates how function operations can create new functions with distinct characteristics. The degree of the polynomial, determined by the highest power of $x$, reveals the function's long-term behavior and its potential number of roots. The coefficients of the polynomial, in this case 1 and -3, influence the shape and position of the graph, providing valuable insights into the function's behavior.

The function $(s-t)(x) = x^3 - 3x^2$ can be analyzed further to understand its key features. For instance, finding the roots of the equation $x^3 - 3x^2 = 0$ reveals the points where the function intersects the x-axis. Factoring the expression, we get $x^2(x - 3) = 0$, which yields the roots $x = 0$ (with multiplicity 2) and $x = 3$. These roots indicate that the function touches the x-axis at $x = 0$ and crosses it at $x = 3$. Determining the function's critical points, where the derivative is zero or undefined, helps identify local maxima and minima. The derivative of $(s-t)(x)$ is $3x^2 - 6x$, which equals zero when $x = 0$ and $x = 2$. These critical points suggest potential turning points in the graph of the function. By analyzing the second derivative, we can determine the concavity of the function and further refine our understanding of its behavior. The result, $(s-t)(x) = x^3 - 3x^2$, serves as a foundation for a comprehensive analysis of the function's properties, demonstrating the power of function operations in revealing mathematical relationships.

Visualizing (s-t)(x): Graph and Interpretation

#h2 To gain a deeper understanding of the function $(s-t)(x) = x^3 - 3x^2$, visualizing its graph is immensely helpful. The graph provides a visual representation of the function's behavior, revealing its key characteristics and properties. By plotting the function on a coordinate plane, we can observe its shape, intercepts, turning points, and overall trend. The graph serves as a powerful tool for interpreting the mathematical expression and connecting it to geometric intuition. The visual representation enhances our comprehension of the function's behavior and allows us to make predictions about its values for different inputs.

The graph of $(s-t)(x) = x^3 - 3x^2$ exhibits several key features. As we previously determined, the function has roots at $x = 0$ and $x = 3$, which correspond to the points where the graph intersects the x-axis. The root at $x = 0$ has a multiplicity of 2, indicating that the graph touches the x-axis at this point but does not cross it. The root at $x = 3$ is a simple root, meaning the graph crosses the x-axis at this point. The critical points, where the derivative is zero, occur at $x = 0$ and $x = 2$. These critical points correspond to local extrema on the graph. At $x = 0$, the function has a local maximum, and at $x = 2$, the function has a local minimum. The overall shape of the graph is a cubic curve, characteristic of cubic polynomials. The graph rises steeply for large positive values of $x$, reflecting the dominant term $x^3$. For large negative values of $x$, the graph falls steeply, also due to the $x^3$ term. The graph's behavior between the roots and critical points provides a detailed picture of the function's behavior. By visualizing the graph, we can readily identify the intervals where the function is increasing or decreasing, concave up or concave down, and its overall trend. The visual representation complements the algebraic analysis, providing a comprehensive understanding of the function $(s-t)(x) = x^3 - 3x^2$. Graphing the function provides an intuitive understanding of its behavior and reinforces the connection between algebraic expressions and geometric representations.

Real-World Applications of Function Subtraction

#h2 Function subtraction, while a fundamental mathematical concept, has a surprising number of real-world applications. Understanding how to subtract functions allows us to model and analyze situations where we need to compare or find the difference between two quantities that vary with the same input. These applications span various fields, from economics and physics to computer science and engineering. By recognizing the underlying mathematical structure, we can apply function subtraction to solve practical problems and gain insights into real-world phenomena. The ability to model and analyze differences between quantities is crucial in decision-making and problem-solving across diverse disciplines. Function subtraction provides a powerful tool for understanding and quantifying these differences.

In economics, function subtraction can be used to model profit, which is the difference between revenue and cost. If we have a revenue function $R(x)$ that represents the total income from selling $x$ units of a product and a cost function $C(x)$ that represents the total cost of producing $x$ units, the profit function $P(x)$ can be expressed as $P(x) = R(x) - C(x)$. Analyzing the profit function allows businesses to determine the optimal production level that maximizes profit. In physics, function subtraction can be used to calculate the net force acting on an object. If we have two forces, $F_1(t)$ and $F_2(t)$, acting on an object at time $t$, the net force $F_{net}(t)$ is given by $F_{net}(t) = F_1(t) - F_2(t)$. This allows us to analyze the motion of the object under the influence of these forces. In computer science, function subtraction can be used in image processing to detect edges or differences between images. By subtracting the pixel values of two images, we can highlight areas where significant changes occur. This technique is used in various applications, such as object recognition and video surveillance. In engineering, function subtraction can be used to analyze the performance of systems. For example, if we have a desired output function $D(t)$ and an actual output function $A(t)$ for a control system, the error function $E(t)$ can be expressed as $E(t) = D(t) - A(t)$. This allows engineers to assess the system's accuracy and make necessary adjustments. These examples illustrate the wide range of real-world applications of function subtraction, highlighting its importance in various fields.

Practice Problems: Mastering Function Subtraction

#h2 To solidify your understanding of function subtraction, working through practice problems is essential. Practice allows you to apply the concepts learned and develop problem-solving skills. By tackling different types of problems, you can identify areas where you need further clarification and refine your understanding. Practice problems help bridge the gap between theoretical knowledge and practical application, building confidence and proficiency in function subtraction.

Here are a few practice problems to test your understanding:

  1. Given $f(x) = 2x^2 + 3x - 1$ and $g(x) = x^2 - 2x + 4$, find $(f-g)(x)$.
  2. Given $p(x) = \sqrt{x+2}$ and $q(x) = x - 3$, find $(p-q)(x)$ and its domain.
  3. If $h(x) = \frac{1}{x}$ and $k(x) = x + 1$, find $(h-k)(x)$.
  4. Let $u(x) = |x|$ and $v(x) = x^2$. Determine $(u-v)(x)$.

Solving these problems involves applying the definition of function subtraction, which is $(f-g)(x) = f(x) - g(x)$. For each problem, you need to substitute the given functions into this equation and simplify the resulting expression. Pay attention to algebraic manipulations, such as combining like terms and simplifying fractions. For problems involving radicals or rational functions, remember to consider the domain of the resulting function. The domain is the set of all possible input values for which the function is defined. For example, the domain of a square root function is the set of all non-negative real numbers, and the domain of a rational function excludes values that make the denominator zero. By working through these practice problems, you will gain confidence in your ability to perform function subtraction and handle various types of functions. The more you practice, the more comfortable you will become with the concepts and techniques involved. Practice is key to mastering function subtraction and building a strong foundation in mathematics.

Conclusion: The Power of Function Operations

#h2 In conclusion, understanding function operations, particularly function subtraction, is crucial for success in mathematics and its applications. The expression $(s-t)(x)$, representing the difference between two functions, exemplifies a fundamental operation that allows us to analyze and manipulate mathematical relationships. By mastering the concept of function subtraction, we gain a powerful tool for solving problems and understanding real-world phenomena. The ability to combine functions through subtraction opens up a wide range of possibilities for modeling and analyzing complex systems. The step-by-step solution presented in this article provides a clear and concise approach to finding $(s-t)(x)$, and the practice problems offer opportunities to solidify your understanding.

Function subtraction is not just an abstract mathematical concept; it has practical applications in various fields, including economics, physics, computer science, and engineering. From calculating profit to determining net force, function subtraction provides a framework for understanding and quantifying differences between quantities. The visual representation of functions, such as the graph of $(s-t)(x) = x^3 - 3x^2$, enhances our comprehension and allows us to connect algebraic expressions to geometric intuition. By exploring the graph, we can identify key features of the function, such as roots, critical points, and intervals of increase and decrease. Mastering function subtraction and other function operations is essential for advancing in mathematics and related disciplines. It provides a foundation for more advanced topics, such as calculus and differential equations. The ability to manipulate and analyze functions is a valuable skill that will serve you well in your academic and professional pursuits. The power of function operations lies in their versatility and their ability to provide insights into complex relationships. By understanding and applying these operations, we can unlock a deeper understanding of the world around us.