Finding f/g: Composite Functions

In summary, the conversation is discussing finding the composite function of $f$ and $g$ given that $f(x)=x^2+1$ and $g(x)=1/x$. The final solution is $f \circ g (x)=\frac{1}{x^2}+1$, and an additional step of finding the quotient $\frac{f}{g}$ is also mentioned.
  • #1
needhelpplease
14
0
The questions is asking me to find \frac{f}{g} basically , the question is asking me to find the answer , even though i know it, i can't get my head around it.

the composite function is

f(x)=x^2+1
g(x)=1/x

we need to find foG (f of g) [composite functions].
 
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  • #2
HelpPlease said:
The questions is asking me to find \frac{f}{g} basically , the question is asking me to find the answer , even though i know it, i can't get my head around it.

the composite function is

f(x)=x^2+1
g(x)=1/x

we need to find foG (f of g) [composite functions].

Thank you solved.Divide them both so x^2+1 / 1/x
switch them to multiply so it's going to be x^2+1/x
 
  • #3
$f \circ g(x)= f(g(x))=\frac{1}{x^2}+1$
 
  • #4
Additionally, the quotient (which is not the composite $f \circ g$) is:
$$\frac fg(x) = \frac{f(x)}{g(x)}=\frac{x^2+1}{1/x}=(x^2+1)x=x^3+x$$
 
  • #5
Just to add an intermediary step:

\(\displaystyle (f\circ g)(x)=f(g(x))=f\left(\frac{1}{x}\right)=\left(\frac{1}{x}\right)^2+1=\frac{1}{x^2}+1\)
 

Related to Finding f/g: Composite Functions

What is a composite function?

A composite function is a combination of two or more functions where the output of one function becomes the input of another function. It can be written as f(g(x)) and is read as "f of g of x".

How do you find the composite of two functions?

To find the composite of two functions, you first plug in the inner function (g(x)) into the outer function (f(x)). This means that the output of g(x) becomes the input of f(x). The result will be a new function, f(g(x)).

What is the purpose of finding f/g?

The purpose of finding f/g is to simplify a complicated function into smaller, more manageable parts. It can also help to solve equations and analyze the relationship between two variables.

Can any two functions be composed?

No, not all functions can be composed. For a composite function to exist, the output of the inner function must match the input of the outer function. This means that the domains and ranges of the two functions must be compatible.

What are some real-life applications of composite functions?

Composite functions are used in various fields such as physics, engineering, economics, and computer science. They can be used to model complex systems, analyze data, and make predictions.

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