SOLUTION: Give an example of a function, f(x), with a domain of (0,5] and a range of [0,∞)

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Question 1129635: Give an example of a function, f(x), with a domain of (0,5] and a range of [0,∞)
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
An example of a function, f(x), with a domain of (0,5] and a range of [0,infinity) is following:
f%28x%29+=+%285+-+x%29%2F%282x%29 when 0+%3C+x+%3C=5
to prove:
x=0 , then f%28x%29=+%285-0%29%2F%280%29+=+indefinite+=infinity
x+=+5, then f%28x%29=+0%2F10=+0
thus, function of f%28x%29+=+%285+-+x%29%2F%282x%29 have a domain of (0,5] and a range of [0,infinity)


another example:
The domain is (0,5], which includes all real numbers between 0 and 5, excluding 0 and including 5.
The functions that do not have 0 in its domain are for example: y=1%2Fx .
The domain of y=1%2Fx+is all the real numbers except 0,i.e., (-infinity,0) U (0,infinity).
To find a way to exclude the negative numbers from the domain is by remembering that the radicand of a square root cannot be negative.
So having that in mind, and applying that to the example above gives the following result: y=1%2Fsqrt%28x%29, and its domain is (0,infinity).

The domain also cannot+include any+number+greater than 5, therefore y=sqrt%285-x%29+%2F+sqrt%28x%29
This function requires 5-x+%3E=+0 (for the top) and x%3E+0 (for the bottom).
So the domain of y=sqrt%285-x%29+%2F+sqrt%28x%29 is (0,5].
Now about the range: square roots are non-negative, so y cannot+be negative.
When x=5, y=0, which is the smallest value of y.

On can note that x gets closer and closer to 0, the numerator gets closer and closer to sqrt%285%29 , and the denominator gets even to 0+(still being positive).
Since y=+sqrt%285-x%29%2Fsqrt%28x%29+=+sqrt%28%285-x%29%2Fx+%29
the square root function is an increasing function, we can just consider+%285-x%29%2Fx
As the denominator gets smaller, the expression %285-x%29%2Fx gets bigger.
So, the function y=+sqrt%28%285-x%29%2Fx+%29 satisfies the requirement of the posted question.