Math Problem Statement

1. Let f, g, h be functions from Z to Z defined as f(x) = x + 5, g(x) = x - 2, h(x) = x^3 for all x ∈ Z. Find f ∘ g, g ∘ f, h ∘ g, g ∘ h, f ∘ h, h ∘ f. 2. Let f: R → R defined as f(x) = x - 1 for all x ∈ R and g: R → R defined as g(x) = x + 1 for all x ∈ R. Find f ∘ g, g ∘ f, f ∘ f, and g ∘ g.

Solution

It looks like you've uploaded an image containing two homework problems related to function composition. Let me go over both problems and their solutions in detail:

Problem 1:

Let ff, gg, and hh be functions from Z\mathbb{Z} (the set of integers) to Z\mathbb{Z}, defined as:

  • f(x)=x+5f(x) = x + 5
  • g(x)=x2g(x) = x - 2
  • h(x)=x3h(x) = x^3

We need to find the following compositions:

  • fgf \circ g
  • gfg \circ f
  • hgh \circ g
  • ghg \circ h
  • fhf \circ h
  • hfh \circ f

Solution:

  1. fg=f(g(x))=f(x2)=(x2)+5=x+3f \circ g = f(g(x)) = f(x - 2) = (x - 2) + 5 = x + 3
  2. gf=g(f(x))=g(x+5)=(x+5)2=x+3g \circ f = g(f(x)) = g(x + 5) = (x + 5) - 2 = x + 3
  3. hg=h(g(x))=h(x2)=(x2)3h \circ g = h(g(x)) = h(x - 2) = (x - 2)^3
  4. gh=g(h(x))=g(x3)=x32g \circ h = g(h(x)) = g(x^3) = x^3 - 2
  5. fh=f(h(x))=f(x3)=x3+5f \circ h = f(h(x)) = f(x^3) = x^3 + 5
  6. hf=h(f(x))=h(x+5)=(x+5)3h \circ f = h(f(x)) = h(x + 5) = (x + 5)^3

Problem 2:

Let ff and gg be functions from R\mathbb{R} (the set of real numbers) to R\mathbb{R}, defined as:

  • f(x)=x1f(x) = x - 1
  • g(x)=x+1g(x) = x + 1

We need to find the following compositions:

  • fgf \circ g
  • gfg \circ f
  • fff \circ f
  • ggg \circ g

Solution:

  1. fg=f(g(x))=f(x+1)=(x+1)1=xf \circ g = f(g(x)) = f(x + 1) = (x + 1) - 1 = x
  2. gf=g(f(x))=g(x1)=(x1)+1=xg \circ f = g(f(x)) = g(x - 1) = (x - 1) + 1 = x
  3. ff=f(f(x))=f(x1)=(x1)1=x2f \circ f = f(f(x)) = f(x - 1) = (x - 1) - 1 = x - 2
  4. gg=g(g(x))=g(x+1)=(x+1)+1=x+2g \circ g = g(g(x)) = g(x + 1) = (x + 1) + 1 = x + 2

Do you have any specific questions, or would you like further details on any part of these solutions?

Here are 5 related questions to expand on the topic:

  1. What would the composition hhh \circ h be for the first set of functions?
  2. Can we generalize the results of fff \circ f and ggg \circ g for arbitrary functions f(x)=x+cf(x) = x + c and g(x)=xcg(x) = x - c?
  3. How would the results change if f(x)f(x) and g(x)g(x) were non-linear functions (e.g., f(x)=x2f(x) = x^2)?
  4. What are the conditions under which fg=gff \circ g = g \circ f?
  5. Can you explain the inverse function concept in the context of these function compositions?

Tip: When composing functions, always evaluate the inner function first and then apply the outer function. This order is critical in obtaining the correct result.

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Math Problem Analysis

Mathematical Concepts

Function Composition
Algebra
Real Numbers
Integer Functions

Formulas

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

Theorems

Composition of Functions

Suitable Grade Level

Grades 9-12