Usually people keep it visible, as it is very useful and extensively used. Some people do hide it though. They can find it obtrusive. The fill options appearing sometimes is found obtrusive too. Some people prefer to use the other methods for filling that Excel provides instead of the Fill Handle. So there are some reasons for hiding it.
The fill handle can be turned off in the Excel options, though it is more useful to have it on.
There is no step function in Excel. However, you can use excel to create a Step Function Chart. See related links for a video to explain the process.
Function
There is no function of that name in Excel. There is a function called VLOOKUP which stands for Vertical Lookup, and is probably what you mean.
In Excel Where are the various function categories stored on the Ribbon?
functions of excel
square handle
A nested if.
In Excel, the ACos function returns the arccosine (in radians) of a number.The syntax for the ACos function is:ACos( number )number is a number between -1 and 1. It is the cosine of the angle that you wish to find.Applies To:Excel 2007, Excel 2003, Excel XP, Excel 2000
Excel does not have a native BOXPLOT function, but you can replicate the function by following the instructions in the related links.
A function can reference cells or named ranges in the function.
You can use the clipboard in Excel. It is a facility as opposed to a traditional function, like the SUM function or AVERAGE or MAX and other functions that are built in to Excel.