find the point(s) of inflection on the function f(x)= 10x + 10/x

Answer 1

f' = 10 - 10/x^2
f" = 0 - 10 [ -2/x^3] = 20/x^3
I do not see anyplace where the curvature passes through zero
except at x = +/- infinity

Answer 2

find the point(s) of inflection on the function f(x)= 10/x + 10/x^2