Is #f(x) =(x-2)^2(x+6)(x-3)# concave or convex at #x=0#?

1 Answer
Dec 29, 2017

#f''(0)=-52<0quad=>quad# function is concave #nnn#

Explanation:

#f(x)=(x−2)^2(x+6)(x−3)#


#f'(x)=2(x−2)(x+6)(x−3)+(x−2)^2(x-3+x+6)#

#f'(x)=(x−2)(4x^2+5x−42)#


#f''(x)=(4x^2+5x−42)+(x−2)(8x+5)#

#f''(0)=(−42)+(−2)(+5)=-42-10=-52#

#f''(0)<0quad=>quad# function is concave #nnn# ("spill the water")