Composition of Functions (check me)

Click For Summary
SUMMARY

The discussion centers on the composition of functions, specifically f(x) = x² + 2 and g(x) = √x. The correct compositions are f ∘ g = f(g(x)) = x + 2, valid for all x in (-∞, +∞), and g ∘ f = g(f(x)) = √(x² + 2), also valid for all x in (-∞, +∞). However, it is crucial to note that g(x) is only defined for x in [0, +∞), which affects the domain of the composition g ∘ f.

PREREQUISITES
  • Understanding of function composition
  • Knowledge of square root functions
  • Familiarity with domain restrictions in mathematics
  • Basic algebra skills
NEXT STEPS
  • Study the properties of function composition in detail
  • Learn about domain and range restrictions for composite functions
  • Explore the implications of function composition on graphing
  • Review examples of compositions involving piecewise functions
USEFUL FOR

Students studying algebra, mathematics educators, and anyone looking to deepen their understanding of function composition and its implications in various mathematical contexts.

Lynne
Messages
12
Reaction score
0
Hi,

Homework Statement


Given:[tex]f(x)=x^2+2[/tex] and [tex]g (x)=\sqrt{x}[/tex]

Find: [tex]f \circ g[/tex] and [tex]g \circ f[/tex]

2. The attempt at a solution
[tex]f \circ g =f(g(x))=x+2[/tex], where [tex]x\in (-\infty ; +\infty)[/tex]

[tex]g \circ f =g(f(x))=\sqrt{x^2+2}[/tex] where [tex]x\in (-\infty ;+ \infty)[/tex]

I haven't done this for a while, and I'm not sure about my solution. Is it correct?
 
Physics news on Phys.org
Almost. Except g(x) is only defined for x in [0,infinity).
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K