solving cubic

Let f(x) = 0.25x^3 - 2x^2 + 3x
0.25x^3 - 2x^2 + 3x = 0
x^3 - 8x^2 + 12x = 0
x(x^2 - 8x + 12) = 0
x(x - 2)(x - 6) = 0
x = 0, x = 2 or x = 6
As x < 0, f(x) < 0, i.e. f(x) is decreasing.
As x > 6, f(x) > 0, i.e. f(x) is increasing.
For relative max point and min point, you could find it your self by differentiation.
So the curve should be as follows:

圖片參考：http://i453.photobucket.com/albums/qq252/tomchan1216/ScreenHunter_01Jan122306.jpg