1. ## inflection

Let
f(x) = (x + 1)^2(x-2).
(a) Find the maximum and minimum values of
f(x);
(b) A point of inflection is a point where the graph changes direction of
concavity, i.e. a point where
f''(x) = 0. Find the inection point(s) of

f, and determine where the function is concave up and concave down

2. What problems are you having? What's your working so far?

3. ## how to go about

first i let x=0
i got f(x)=-2 , this is the turning point?

4. Originally Posted by mathseek
first i let x=0
i got f(x)=-2 , this is the turning point?
The maxima/minima of a curve is given by the point when it's gradient is zero. The gradient of a curve is given by the first derivative of the function the describes it.

In other words:

$m = f'(x) = 0$

So, find f'(x), set it equal to zero, and solve for x. This will give you the x co-ordinates of the maxima/minima. THEN plug that value back into the original equation, f(x), to find the y value. (y=f(x)).