how do I find the domain?

Question

f(x) = 7 - the square root of x - 3

Answer 1

The variable x can take any value so the domain is from - infinity to + infinity in real space (so any real number will do) so long as x-3>0 x>3. if not say good bye to the real domain since we end up with a negative number under the square root. So we have 3< x < infinity is the domain you are looking for

Explanation: By definition the domain of a real function ( f(x) in our case) is the set of all real numbers variable x can take such that the f(x) remains in the range of real numbers.

Reference http://www.analyzemath.com/DomainTest/answers_domain.html

Answer 2

you whatn to have a posetve number under the square root so the domain under there has to be greater than or = 3. the scond part of the proble is a 7 wich dose not efect the domain in this problem.

Answer 3

Hi,

Let's use sqrt(x) for square root of x.

Now we have
f(x) = 7-sqrt(x-3)

The (real) domain for f(x) will be defined as the values of x which will give you a real answer for f(x).

This implies that
sqrt (x-3)>0
(x-3)>0
x>3.

Hope that helps,
Matt