Find the x-coodinate of the local maximum of fx x3 - 23x2

Question

1. Determine the intervals where the function below is decreasing: f(x) = 2x³ = 9x² + 12x + 54.

2. Find the x-coodinate of the local maximum of f(x) = x³ - 2.3x² - 2.8x

3. Find the x-coodinate of the local maximum of f(x) = x³ - 2.1x² -1.7x

4. Find the absolute minimum value of the following function on the interval [0,2]. f(x) = x² - 4.6x + 1.