Chapter 10: Problem 28
(a) Write $$h(x, y)=\sqrt{x+y}$$ as a composition of two functions.
Short Answer
Expert verified
\( h(x, y) = f(g(x,y)) \) with \( f(u) = \sqrt{u} \) and \( g(x,y) = x+y \).
Step by step solution
01
Understand the composition requirement
We need to express the function \( h(x, y) = \sqrt{x+y} \) as a composition of two functions, say \( f \) and \( g \), such that \( h(x, y) = (f \circ g)(x,y) = f(g(x,y)) \).
02
Choose an inner function
We select the inner function \( g(x,y) \) to simplify the input to the square root. A good choice is \( g(x,y) = x+y \). This gathers the expressions inside the square root together.
03
Define the outer function
With \( g(x,y) = x+y \), the outer function \( f \) should apply the square root to the input. Hence, define \( f(u) = \sqrt{u} \).
04
Verify the composition
Compose the functions as \( f(g(x,y)) = f(x+y) = \sqrt{x+y} \), which matches the original function \( h(x, y) \). Therefore, the composition is correct.
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.
Understanding the Inner Function
In the context of function composition, the **inner function** is an essential building block that forms the base of a composite function structure. When given a function like \( h(x, y) = \sqrt{x+y} \), our goal is to express it as a function composition. Here, the inner function will typically handle the initial transformation of input variables.
- The choice of the inner function determines how we preprocess or combine inputs before the final operation.
- For \( h(x, y) \), we selected the inner function \( g(x,y) = x + y \).
- This step involves aggregating or transforming inputs to simplify subsequent operations.
Defining the Outer Function
The **outer function** acts as the final step in processing the output from the inner function in a function composition sequence. Put simply, it's the function that directly computes the result after the initial inputs have been transformed by the inner function.
- In our case, after the inner function \( g(x, y) = x + y \) collects and aggregates the terms, the role of the outer function is to perform the square root.
- Defined as \( f(u) = \sqrt{u} \), this outer function takes the sum produced by \( g \) and performs the desired operation — in this instance, square rooting.
Exploring Mathematical Functions
Mathematical functions are fundamental tools in mathematics that map inputs to outputs according to specific rules. They can represent a variety of real-world processes and computations, offering critical insights and simplifying complex operations:
- Functions consist of an input domain (where the input values are drawn from) and a codomain (where the output values land).
- For example, our function \( h(x, y) = \sqrt{x+y} \) takes inputs \( x \) and \( y \) and transforms them into an output that belongs to the set of non-negative real numbers.
- In composition, each function — inner or outer — plays a specific role in processing these inputs, leading to the final computed result.