Can someone Help?

For a Function F(X) = B^X the Domain is:

All Reals
All Reals Where X 0
All Reals where y 0
(0, *Infinty*)

Question

Can someone Help?

For a Function F(X) = B^X the Domain is: 

All Reals
All Reals Where X > 0 
All Reals where y > 0
(0, *Infinty*)

allank · Answer

I'm thinking All Reals.

allank · Answer

Let's say the function is f(x) = 2^x
Try x=-1, f(x) = 2^(-1) = 1/2  That knocks out choice B and D.

allank · Answer

Try setting y=0. 
0=2^x 
log0=xlog2
x=log0/log2
log0 is undefined, thus this knocks out C because there is no value of x that can yield y that is equal to, or less than 0.

anonymous · Answer

Dude Thanks So much! i have one more question to ask but i'll make a new one so you can get another medal :P

allank · Answer

You're welcome =)