A function g is continuous on R and differentiable everywhere except at x=4. Its derivative satisfies:
• g′(x)<0 for x<0,
• g′(0)=0,
• 0<g′(x)≤5 for 0<x<4,
• g′(4) does not exist,
• g′(x)<0 for x>4.
a) State the open interval(s) on which g is strictly increasing.
b) State the open interval(s) on which g is strictly decreasing.
c) Classify x=0 and x=4 as points of local maximum, local minimum, or neither, giving one reason for each.