Eh. Here's the problem:

"A cubic polynomial is given by $\displaystyle f(x)=ax^3+bx^2+30x+k$ where a, b, and k are constants. The function f(x) has a local minimum at (-1,-10) and a point of inflection at x=2.

a) Find the values of a, b, and k.

b) Use the second derivative to verify that (-1,-10) really is a local minimum for your function.

c) Find the location of any local maximums for your function. Verify that they are indeed a local maximum."

Here's what I've done so far..

I've found the first derivative, $\displaystyle f(x)= 3ax^2 + 2bx + 30$

and the second derivative, $\displaystyle f(x)= 6ax + 2b$.

I then plugged the value of x=1 into the first derivative, getting $\displaystyle 3a-2b+30$.

I also plugged the inflection point of x=2 into the second derivative and got

$\displaystyle 12a+2b$.

From there, I can't seem to remember what to do. Help, please? D: