The range of a function is the set of the values of f(x)
when x lies in the domain.
The domain of f(x) is all values
where x – 1 > 0 because if the denominator is 0, we get an indeterminate number
and for x - 1 < 0, the square root is a complex
number.
=> x >
1
f(x) = x/sqrt(x - 1)
f'(x) =
[1*sqrt(x - 1) - x*(1/2)(1/sqrt(x - 1))]/(x - 1)
=>
f'(x) = [(x - 1) - x/2]/(x - 1)^(3/2)
=> f'(x) = (x
- 2)/2*(x - 1)^(3/2)
equating f'(x) = 0, we get x =
2
The function has the minimum value when x =
2
f(2) = 2/sqrt 1 = 2
If x
> 1, f(x) >= 2
The range of the
function is (inf., 2]
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