I'm trying to do the system sum of this equation, but all I've found is the command symsum to do this. However, I don't have the toolbar that this command comes with. Is there any way to either use this command or any other commands I can use to do this?
This is what I got so far. Any help is appreciated.
com_cos = symsum((((-1) ^ k) * x_val ^ (2 * k)) / factorial(2 * k), k = 1..Infinity);