Question

What is the domain of the function f (x) = StartFraction x + 1 Over x squared minus 6 x + 8 EndFraction?

Answer 1

Answer: (-∞, 2)∪(2, 3]∪(4, ∞)

Step-by-step explanation:

Domain is the allowed x values in the function. The numerator, x + 1 will be defined for all numbers. But that fraction wont be, the minute that fractions denominator is equal to zero, your entire function becomes undefined.

So lets figure out what number will make this undefined. Then we'll know the functions domain is everywhere but that x value.

Make x^2 - 6x + 8 = 0

What two numbers multiply to equal +8 but add to equal -6? Thats -4 and -2.

(x - 4)(x - 2) = 0 This means the function is undefined when x equals 4 and 2

(-∞, 2)∪(2, 3]∪(4, ∞)