## Exponential Functions

Complex numbers, rational functions, logarithms, sequences and series, matrix operations, etc.
jwroblewski44
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### Exponential Functions

Hello again.

I just started a chapter on Exponential Functions and am working on their graphs. I've come across a statement that has me confused. The statement is:

"The exponential function f(x)=a^x ( a>0, a doesn't equal 1 ) has domain R and range ( 0, infinity ). The line y=0 ( the x-axis ) is a horizontal asymptote of f...."

I understand the concept of domain and range. But usually range took the form of y | y > 9 ( y where y is greater than 9 ) [just an example]. I have no idea what range of ( 0, infinity ) means. I thought range was the possible range of values the function/expression/etc would produce, as in a value, not a coordinate pair.

stapel_eliz
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If the range is "all y greater than 9", then the range is "from 9 to infinity". In the same way, "from 0 to infinity" means "all y greater than zero".

jwroblewski44
Posts: 13
Joined: Mon Jun 03, 2013 1:49 am
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### Re: Exponential Functions

Ahhh thank you. I forgot that there is more than one form of symbols for describing domain and range. I was familiar with { x | x > 9 } and totally forgot all other methods, i.e. ( 0 , 9 ).