Here is a function: f[x_] := 1\/8\ \((19 + 27\ x + 9\ x\^2 + x\^3)
Now I got that far to get the first and second diferentiation:Solve[f'[x]==0,x],Solve[f''[x]==0,x].
I even managed to plot the graph.
Now what syntax do I use to get the proper y values for the x values?
How do I get Mathematica to put out decimal numbers?
How can I plot specific Points such as an extreme value by markingit with a dot ?
I did not quite understand what the underline is for that one is suposed to place behind the f[x_].
I woul appreciate some help