Is it possible to differentiate (60-x)/1.2?
I'm thinking the answer would be 1/0 which is not possible but I just want to make sure.
No problem. Just do a little algebra first.
f(x)= (60-x)/1.2 = 50 - (5/6) x
The derivative is df/dx = -5/6
How did you get 5/6x?