Thread: concavity

Without using a calculator, find the values of x for which the graph of y=x^3 - 6x^2 is concave downward.


Thanks

Hello, DINOCALC09!

It's pretty straight-foward.
Exactly where is your difficulty?

Find the values of x for which the graph of is concave downward.

First derivative: .

Second Derivative: .

The graph is concave down when the second derivative is negative.

So we have: .


The graph is concave down for

i believe that you messed up on the first derivative and hence the concave down part is x< 2

am i right?

Originally Posted by DINOCALC09

i believe that you messed up on the first derivative and hence the concave down part is x< 2

am i right?

yes you are..