Question

What is the domain of: f(x)=(sqrt(x+6)/(x+7)(x-9)

Answer 1

All real numbers

x ≥ -6, x ≠ 9

x ≠ -7, x ≠ -6, x ≠ 9

x > 0

I think its either B or C...

Answer 2

Well you have to satisfy that the denominator can't equal zero and that the expression under the radical has to be non-negative

Answer 3

If the denominator cant equal zero I get -7 and 9...not sure about the other part. But I think that automatically gives me option C as correct?

Answer 4

You also need x+6>=0 from the radical
If you pick C then you are also including x=9 which should not be a part of the domain

Answer 5

Well that would be x>=-6...
x=-7, x=9 and x>=-6? so which option do I need?

Answer 6

You've mixed up things that should not be included and things that should.
Your domain is all x such that x=/=-7, x=/=9 and x>=-6

Answer 7

Im sorry I still dont understand.

Answer 8

What is confusing. Your domain has to satisfy the conditions listed above. Now see which of the options gives the same restictions