Domain of the function

Question

Find the domain of the function g (x)= square root of 9-9x. Write your answer in interval notation

Answer 1

g(x) = sqr(9-9x)

9-9x > 0

9> 9x

1 > x

x < 1

the domain

in interval notation is (-infinity, 1]

use a bracket to indicate it includes the right end, x can =1

but use a parenthesis to indicate it's an open interval at the left end

as -infinity is not a real number, just a limit that is approached but never reached

otherwise, if x>1, g(x) is an imaginary number

as the square root of 9-9x would be the square root of a negative number

"domain" is limited to real numbers

assuming that, as is likely, you intended to mean g(x) = sqr(9-9x)

and not g(x) = sqr(9) - 9x

if by chance you meant the latter, then the domain is all real numbers

(-infinity, +infinity)