How do you find the domain and range of f(x) = (x+3 )/ (x^2 + 8x + 15)?

1 Answer
Oct 19, 2015

x != -3, -5
Or is can be written as (-oo , -3) uu (-3, -5) uu (-5, oo)
you may have been taught to use '[ ]' for included and '] [' for excluding.

Explanation:

You need to simplify the denominator and find where x = 0.

x^2 +8x + 15

15/3 =5

(x+3)(x+5)

x +3 = 0, x + 5 = 0

x =-3, x = -5

Since the denominator cannot be zero, since 0/0 = "Err",
The domain is x != -3, -5