Consider the function below. (If an answer does not exist, enter DNE.)
f(x) = e^arctan(7x)

I did the problem but I have mistakes on some items. I think the ff. are right:
Vertical Asymptote: x = DNE
Horizontal Asymptote: y = e^-(pi/2), e^(pi/2)
Interval where the function is increasing: All reals
Interval where the function is decreasing: DNE
Local max and min: DNE

I need to know the interval where the function is concave up and down and the inflection point.