Hi. I need to run through an approximation scheme, and one of the variables in the scheme is unknown, but I know what the final answer should be. I want to calculate the value of the unknown by figuring out what it must be for the approximation to equal the expected result after a significant number of iterations. Is there, in MATLAB, some way to use a pronumeral without assigning a value to it? i.e. so that the pronumeral remains in the result. e.g. we might run ten iterations of the program and have a^10 as a factor in the final result, then run it for 1000 iterations and have a^1000 in the final result. I have not been able to figure this out. Maybe there is a 'trick' that can be used for this kind of problem? Thanks in advance.