Let f(x)=sqrtx^2+4 and g(x)=-sqrtx^2-4. Find the domain of..

[justsimplymei]

Let f(x)=sqrtx^2+4 and g(x)=-sqrtx^2-4. Find the domain of (g times f)(x).

the answer is all real numbers. how is this so? please provide a detailed explanation. test is on monday. thanks

 

[tkhunny]

Are you sure it's "times"?

Are you sure you are thinking about the Domain and not the Range? Why would there be restrictions of that f(x). All Real Numbers seems rather apparent.

The exact wording and notation might help.

 

[justsimplymei]

yes, it means multiply. its that little circle mark. 'o' in between f && g in the parenthesis

 

[stapel]

yes, it means multiply. its that little circle mark. 'o' in between f && g in the parenthesis

If the expression uses "that little circle mark", then the notation does not indicate function multiplication (which uses a dot or an "x"), but function composition. :shock:

To learn about this subject, try here:

. . . . .Google results for "composition functions"

Have fun! :wink:

Eliz.

P.S. Welcome to FreeMathHelp!