Math Problem Statement

Find two functions f and g such that (f ∘ g)(x) = h(x). (There are many correct answers. Use non-identity functions for f(x) and g(x).) h(x) = 64x3 + 3x 17 − 64x3

(f(x), g(x)) =

Solution

We are given h(x)=64x3+3x1764x3h(x) = \frac{64x^3 + 3x}{17 - 64x^3} and asked to find two functions f(x)f(x) and g(x)g(x) such that (fg)(x)=h(x)(f \circ g)(x) = h(x). This means that:

(fg)(x)=f(g(x))=h(x)(f \circ g)(x) = f(g(x)) = h(x)

We can break down the composition by identifying possible forms for f(x)f(x) and g(x)g(x).

Step 1: Look for a structure in h(x)h(x)

Notice that h(x)h(x) looks like a rational function, which suggests that we could let g(x)g(x) be a simpler expression inside the rational form, and f(x)f(x) handle the rational part.

One approach would be to let g(x)g(x) capture the polynomial expression inside the rational function, like 64x3+3x64x^3 + 3x, and let f(x)f(x) represent the rational operation (quotient).

Step 2: Define g(x)g(x)

Let: g(x)=64x3g(x) = 64x^3 This is a simple choice that captures the cubic term of h(x)h(x).

Step 3: Define f(x)f(x)

Now, using g(x)=64x3g(x) = 64x^3, the function f(x)f(x) should take this and produce the rational expression in h(x)h(x). So we set: f(x)=x+3x17xf(x) = \frac{x + 3x}{17 - x}

Final Answer:

Thus, we have the following functions: g(x)=64x3g(x) = 64x^3 f(x)=x+3x17xf(x) = \frac{x + 3x}{17 - x} Now, (fg)(x)=f(g(x))=64x3+3x1764x3=h(x)(f \circ g)(x) = f(g(x)) = \frac{64x^3 + 3x}{17 - 64x^3} = h(x), which satisfies the requirement.


Do you want more details on the steps, or any other questions on this?

Here are 5 related questions for deeper understanding:

  1. What if we chose a different function for g(x)g(x)? How would that affect f(x)f(x)?
  2. How can we confirm that the composition (fg)(x)=h(x)(f \circ g)(x) = h(x) is valid for all values of xx?
  3. What is the domain of the function h(x)h(x), and how does it relate to the domains of f(x)f(x) and g(x)g(x)?
  4. Can we express the same h(x)h(x) with trigonometric or logarithmic functions for ff and gg?
  5. How would the composition change if h(x)h(x) were a different type of function, like a polynomial?

Tip: When composing functions, always verify that the output of the inner function fits into the input domain of the outer function!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Function Composition
Rational Functions
Polynomials

Formulas

Function composition: (f ∘ g)(x) = f(g(x))
Rational functions: h(x) = (numerator)/(denominator)

Theorems

Basic properties of function composition

Suitable Grade Level

Grades 11-12 (Precalculus or higher)