Thread: Differentiation

The problem is to determine where the function is increasing, decreasing, concave up and concave down.

1) y=(2x-3)^(1/3)

2) y=1/(1+e^-x)

for the first one, i got the first derivative of (1) 2/3(2x-3)^(-2/3)
but im not sure if this is right.
and i have no idea for the second derivative.
and i really really have no idea for the second problem.

Your first derivative is right!

for the second just differentiate your expression for the first derivative again, you used the chain rule for the first I'm guessing so just use it again.

I get



For the second one rewrite it as



then use the chain rule

I get

Then use the quotient rule on this to get the second derivative