Can I use a 2010 iMac 21.5 inch as a monitor
Is there a way of using a 21.5 inch 2010 imac as an additional screen for my 2017 MacBook air. The imac has a minidisplay port and the MacBook air has a thunderbolt port. I've got a mini display part cable.
I've tried connecting the two with the cable and hitting command f2 with no joy. Are there any other options?
iMac 21.5″, macOS 10.12