Let f(x) = x + 64/x+6(a) Find the domain of f. (Enter your answer using interval notation.)The domain of f is(b) Find the derivative of the function f.(c) Find the domain of f'. (Enter your answer using interval notation.)The domain of f'is(d) Determine the value(s) of x in the domain of f, if any, at which the function is not differentiable. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.)(e) For what values of x does the graph of f have a horizontal tangent? (Enter your answers as a comma-separated list. If ananswer does not exist, enter DNE.)