Question

How do you find the domain of `f( x ) = \frac { x ^ { 2} - x - 12} { x ^ { 2} + 7x - 18}`?

Answer 1

Domain: `x in RR` except `(x = -9 or x = 2)`. In interval notation: `(-oo, -9) uu (-9 ,2) uu (2,oo)`

Explanation:

`f(x)=(x^2-x-12)/(x^2+7x-18) or f(x) = ((x-4)(x+3))/((x+9)(x-2))`

Domain : Input restriction is denominator should not be `0` or

`x+9 != 0 or x != -9 and x-2 !=0 or x != 2`

Domain: `x in RR` except `(x = -9 or x = 2)`. In interval notation:

`(-oo, -9) uu (-9 ,2) uu (2,oo)`

graph{(x^2-x-12)/(x^2+7x-18) [-40, 40, -20, 20]} [Ans]