Find the domain of f for each of the following functions. If you need to enter - or , enter -INFINITY or INFINITY.

f(x) = x+4
------
x^3-9x

a. (-INFINITY,0)(3,INFINITY)
b. ALL REAL NUMBERS
c. ALL REAL NUMBERS - {3}
d. ALL REAL NUMBERS - {-3,3,0}

Question

Find the domain of f for each of the following functions. If you need to enter - or , enter -INFINITY or INFINITY.

f(x) = x+4 
        ------
        x^3-9x

a. (-INFINITY,0)(3,INFINITY)
b. ALL REAL NUMBERS
c. ALL REAL NUMBERS - {3}
d. ALL REAL NUMBERS - {-3,3,0}

dumbcow · Answer

x^3 -9x = 0
x(x^2 -9) =0
x(x+3)(x-3) =0

D

anonymous · Answer

so you always set the denominator to 0 & do nothing with the numerator?