I need to resample a 30m DEM to a 100m slope raster. Do I just resample the 30m DEM directly to the 100m slope raster? or, do I convert the 30m DEM to a 100m DEM and then create a 100m slope raster from the new 100m DEM file?
It would be best to resample the DEM and then create the slope layer.
Take a look at this thread (particularly post 2) from the ESRI forums.
You might end up saving yourself some time this way as well. Resampling a DEM will reduce it's size (in terms of disk space), and should allow the slope tool to process in a shorter amount of time.
Try both and compare. Either will be a compromise on your higher resolution dataset. Hence, there is not 'proper' solution. Just be sure to detail the process you undertook so your work is repeatable.
Yes you can however; if you resample from smaller cell size to a larger cell size can result in the loss of data. If you resample from larger cell size to a smaller does not increase the resolution, it just creates more cells.