Question

Help Please!

Answer 1

A. (-infinity, +infinity)
B. (0,infinity)
C. (1, infinity)
D. (4,infinity)

Answer 2

I believe it is C.

Answer 3

i think you are right too

Answer 4

yeap c is correct

Answer 5

@karim728 thanks!

Answer 6

explanations:
The domain of a polynomial with real coefficients has a domain of (-inf,+inf).
So the domain of the expression b(a(x)) depends on the domain of sqrt(x-4).
We do not want x-4 to be negative, else the result will be complex, so the domain is [4,+inf).

Answer 7

Oops, it's b(a(x)), which means that when x\(\ge\)1, a(x) evaluates to \(\ge\)4, so
[1,+inf) is correct.
Note that the square bracket on the left means 1 is included, and the round bracket on the right means +inf is excluded.