How many real numbers are not in the domain of the function$$f(x) = \frac{1}{x-64} + \frac{1}{x^2-64} + \frac{1}{x^3-64}~?$$
No denominator can = 0 .... so.....
x - 64 = 0
x =64 is not in the domain
x^2 - 64 =0
x^2 =64
x = -8 or x =8 are not in the domain
x^3 - 64 = 0
x^3 =64
x =4 is not in the domain