Domain of g(x) = (x-2)/(x^2-9) |x|≠3

[alpha01]

for g(x) = (x-2) / (x^2 -9)

the domain of the function would be simply to have the denominator not equal to 0, which in this case would be x = 3.

but.. the solution states that it is -3 and 3 cannot be used.

this is confusing seeing that -3^2 -9 = -18 which is not 0.

maybe it means |-3|?

 

[ircdan]

(-3)^2 - 9 = 9-9 = 0

there is a difference,

-3^2 = (-1)*3^2 = -1*9 = -9, but (-3)^2 = (-1*3)^2 = (-1)^2 * 3^2 = 1*9 = 9

 

[alpha01]

i get it. thanks