I have a couple variables that are comprised of two letters like Vi for V initial and Vf for V final.
I solved for X in terms of these variables and now I want to take the limit of my solution as Vi-> 0 and Vf -> 0. But Vi and Vf turn red when typed and I get an unknown option error when I run it.
How can I fix this?
Subject (listing for 'Help with defining variables')