Question

determine the open intervals on which f(x) is increasing, decreasing, concave up and concave down.

f(x)= tanx, -pi/2< x< pi/2

Answer 1

nevermind i figured it out

Answer 2

Good. I was going to suggest you just plot the function.
It increases where the derivative is positive, and is concave upward where the second derivative is positive. tan x is always increasing in that interval