SOLUTION: How do I find the domain of f(x)= 9log(-x)+7? I have looked up how-to videos and they all say to set this up like an inequality but I don't see how this would be set up as an inequ

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: How do I find the domain of f(x)= 9log(-x)+7? I have looked up how-to videos and they all say to set this up like an inequality but I don't see how this would be set up as an inequ      Log On


   

Question 1057383: How do I find the domain of f(x)= 9log(-x)+7? I have looked up how-to videos and they all say to set this up like an inequality but I don't see how this would be set up as an inequality. Thanks!!
Found 2 solutions by Fombitz, math_helper:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
The domain is all values for which your function is defined.
The log function is only defined when the argument(the portion in the parentheses is positive).
So then,
-x%3E0
x%3C0
So the function is defined for all x where x%3C0.
This is the domain, x%3C0.

Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
The domain of f(x) is the set of all values that x can take where f(x) is defined.
For f(x) = 9log(-x)+7, that will be wherever log(-x) is defined, and that will be whenever x < 0 (because then the argument to log( ) will be greater than 0 due to the sign change)
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Ans: domain of f(x) = 9log(-x)+7 is x<0
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