Math Problem Statement

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Express f as a composition of two functions; that is, find g and h such that f = g∘h.

Solution

Let's solve the given problem.

We are tasked with expressing f(x)f(x) as a composition of two functions gg and hh, such that f(x)=(gh)(x)=g(h(x))f(x) = (g \circ h)(x) = g(h(x)).

Let’s analyze each of the functions provided to express them as compositions:

(a) f(x)=3sin(x2)f(x) = 3\sin(x^2)

We can break this down as follows:

  • Let h(x)=x2h(x) = x^2 (the inner function).
  • Let g(x)=3sin(x)g(x) = 3\sin(x) (the outer function).

Thus, f(x)=g(h(x))=3sin(x2)f(x) = g(h(x)) = 3\sin(x^2).

Answer for part (a):

  • g(x)=3sin(x)g(x) = 3\sin(x)
  • h(x)=x2h(x) = x^2

(b) f(x)=3sin2(x)+4sin(x)f(x) = 3\sin^2(x) + 4\sin(x)

This can be rewritten using composition:

  • Let h(x)=sin(x)h(x) = \sin(x) (the inner function).
  • Let g(x)=3x2+4xg(x) = 3x^2 + 4x (the outer function, where xx represents sin(x)\sin(x)).

Thus, f(x)=g(h(x))=3h(x)2+4h(x)=3sin2(x)+4sin(x)f(x) = g(h(x)) = 3h(x)^2 + 4h(x) = 3\sin^2(x) + 4\sin(x).

Answer for part (b):

  • g(x)=3x2+4xg(x) = 3x^2 + 4x
  • h(x)=sin(x)h(x) = \sin(x)

(c) f(x)=(1+sin(x2))3f(x) = (1 + \sin(x^2))^3

This can be broken down as:

  • Let h(x)=1+sin(x2)h(x) = 1 + \sin(x^2) (inner function).
  • Let g(x)=x3g(x) = x^3 (outer function).

Thus, f(x)=g(h(x))=(1+sin(x2))3f(x) = g(h(x)) = (1 + \sin(x^2))^3.

Answer for part (c):

  • g(x)=x3g(x) = x^3
  • h(x)=1+sin(x2)h(x) = 1 + \sin(x^2)

(d) f(x)=1x3f(x) = \sqrt{1 - \sqrt[3]{x}}

Here’s how we can express it:

  • Let h(x)=x3h(x) = \sqrt[3]{x} (inner function).
  • Let g(x)=1xg(x) = \sqrt{1 - x} (outer function).

Thus, f(x)=g(h(x))=1x3f(x) = g(h(x)) = \sqrt{1 - \sqrt[3]{x}}.

Answer for part (d):

  • g(x)=1xg(x) = \sqrt{1 - x}
  • h(x)=x3h(x) = \sqrt[3]{x}

Would you like further explanation on any part of this? Here are some related questions to expand your understanding:

  1. How do you identify inner and outer functions when decomposing a function?
  2. What are some common functions that appear frequently in function compositions?
  3. How do we verify that a composition of functions equals the original function?
  4. What are the applications of function compositions in real-world problems?
  5. Can all functions be decomposed into compositions of simpler functions?

Tip: When identifying compositions, look for nested operations, where one function's output becomes the input of another!

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Math Problem Analysis

Mathematical Concepts

Function Composition
Trigonometry
Algebra

Formulas

f(x) = g(h(x))

Theorems

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Suitable Grade Level

Grades 9-12