SOLUTION: How to take the domain of: sqrt(x-1)-ln(15-x) Please show how to solve Thank you

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Question 1006911: How to take the domain of:
sqrt(x-1)-ln(15-x)
Please show how to solve
Thank you

Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
No log of negative number, so ln(15-x) can only accept x%3C=15.

The square root must be for non-negative argument, so x-1 must be nonnegative.
x-1%3E=0
x%3E=1


The domain is the intersection of these requirements.
highlight%281%3C=x%3C=15%29

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

How to take the domain of:
sqrt(x-1)-ln(15-x)
Please show how to solve
Thank you
Set each expression > 0, since the domain MUST be POSITIVE
We then get: x - 1 > 0______x > 1
Also, 15 - x > 0
- x > - 15
x+%3C+%28-+15%29%2F%28-+1%29 ---- Inequality sign changes when dividing by a negative number (< 0)
x < 15
Therefore, domain, or highlight_green%281+%3C+x+%3C+15%29