I'm having trouble entering the subscript "n-1" after "prev" The - 1 doesn't stay with n as part of subscript.
Any suggestions? I'm using PTC Mathcad Prime 3.1
Solved! Go to Solution.
Guess the variable the derivative is taken wrt can't be a vector element.
Workaround could be to assign the derivative function to a function func1(prev) and then use that function with the indexed prev[n as argument.
But in Prime you should be able to use the prime symbol ' instead of the derivative operator. Then it should work the way you had set up even with an indexed prev.
I guess I misunderstood your problem in the first place. What you posted works, but your goal is to get rid of the variable prev and use the vector element t_(n-1) directly.
This also does not work with the Prime operator.
As a workaround you could define a local function in your program with the name func'. here the ' is the normal apostrophe, not the Prime symbol from the "operators" menu. On the RHS you either use the prime symbol as shown or the derivative operator you had used.