1. Determine the intervals where f(x) is increasing and decreasing and the local extrema. f(x) = 18x – 15x² – 4x3 %3D 2. Determine the intervals where f(x) is concave up, concave down, and any...

If someone could please help me out that'd be great. My teacher's (she's nice don't get me wrong!) is just really bad at explaining things. I think she uses a number line with like three numbers or something to solve this? I really have no idea though.

Extracted text: 1. Determine the intervals where f(x) is increasing and decreasing and the local extrema. f(x) = 18x – 15x² – 4x3 %3D 2. Determine the intervals where f(x) is concave up, concave down, and any inflection points. f (x) = x* - 3x3+ 3x2 – x