Answer:
D. (-2,-5), (0, -7), (1, -4)
Step-by-step explanation:
From Function Theory we must remember that range of a function is the set of images related to elements of the domain. In this case, we must find the image of each of the three elements that forms the domain of , which are:
,
and
.
Then we proceed to find all elements of range:
Which corresponds to option D.
You can use the definition of logarithm and the fact that a positive number raised to any power will always stay bigger than 0.
The domain of the given function is {x | x > 1 and a real number }
The range of the given function is (set of real numbers)
If a is raised to power b is resulted as c, then we can rewrite it that b equals to the logarithm of c with base a.
Or, symbolically:
Since c was the result of a raised to power b, thus, if a was a positive number, then a raised to any power won't go less or equal to zero, thus making c > 0
<h3>How to use this definition to find the domain and range of given function?</h3>Since log(x-1) is with base 10 (when base of log isn't specified, it is assumed to be with base 10) (when log is written ln, it is log with base e =2.71828.... ) thus, we have a = 10 > 0 thus the input x-1 > 0 too.
Or we have:
x > 1 as the restriction.
Thus domain of the given function is {x | x > 1 and a real number }
Now from domain, we have:
(log(x-1) > -infinity since log(0) on right side have arbitrary negatively large value which is denoted by -infinity)
Thus, range of given function is whole real number set (since all finite real numbers are bigger than negative infinity)
Thus, the domain of the given function is {x | x > 1 and a real number }
The range of the given function is (set of real numbers
Learn more about domain and range here:
