What is the sum of all real numbers x that are not in the domain of the function
f(x) = 1/(x^2 - 7) + 1/(x^3 - 7) + 1/(x^4 - 7)?
If ANY of the denominators = 0 then that value of x is not in the domain
x = ± \(\sqrt{7}\) , \(\sqrt[3]{7}\) , ± \(\sqrt[4]{7}\) all are not in the domain the sum would be \(\sqrt[3]{7}\)
