# Help with two functions...

• Mar 18th 2013, 09:19 PM
curt26
Help with two functions...
f(x)= x/2-x and g(x)=1/x

domain f o g

Any help with this question would be much appreciated. Thank you!
• Mar 18th 2013, 09:49 PM
Punch
Re: Help with two functions...
Quote:

Originally Posted by curt26
f(x)= x/2-x and g(x)=1/x

domain f o g

Any help with this question would be much appreciated. Thank you!

Is the question is asking for the domain of $fg$?

If so, then the answer is the domain of the function g(x) which has to be provided in the question.
• Mar 18th 2013, 09:52 PM
princeps
Re: Help with two functions...
Quote:

Originally Posted by curt26
f(x)= x/2-x and g(x)=1/x

domain f o g

Any help with this question would be much appreciated. Thank you!

$f \circ g=f(g(x))=\frac{\frac{1}{x}}{2-\frac{1}{x}}=\frac{1}{2x-1}$

Domain : $\forall x \in \mathbb{R} ~\text{except}~ x=\frac{1}{2} ~\text{and}~x=0$
• Mar 20th 2013, 04:02 AM
jennyking001
Re: Help with two functions...
x/2-x or x/(2-x) ?