let f(x) =ax^3+bx^2+cx+d. Determine the values of A,b,c and d if f(x) has a point of inflection at (0,2) and a local maximum at (2,6).

I got d=2, and subbed (2,6) to get 2=4a+2b+c as my first equation, but I don't know what to do next

ok I figured it out and got f(x)=(-1/4)x^3 +3x+2