Question

g(x)=(x+3)/(x^2+x-72) find ALL values of x that are NOT in the domain of g.. so I came up with (-inf,-9)U(-9,8)U(8,inf) as domain.. how would I list all values NOT in the domain?

Answer 1

(x^2+x-72)
factored into (x+9)(x-8)

we can't have -9 and 8 since that would turn our denominator to zero

Answer 2

Hrm.. (x+9)(x-8) is the answer? o_O

Answer 3

no, the answer is -9 and 8
because if you plug in either of those number into
(x+9)(x-8)
you would get zero

Answer 4

Ohhh ok.. Thank you kind sir!