Find the point of

local max. value is 251 at x = 8 and local min. value is −5 at x = 0

‘^}(x)=-3x²+24x=0

⇒ -3x(x-8)=0

⇒ x=0,8

F^’’(x)=-6x+24

F^’’(0)>0, 0 is the point of local min.

F^’’(8)<0, 8 is the point of local max.

F(8)=251 and f(0)=-5