Question: I realize this is a somewhat vague question so I'll do my best. If I have a number like `n = 0.783325849821429`, is there a way to display even more decimal places? This was produced with format long. The problem is that I'm doing error estimate calculations with sine and there comes a point where the estimation is so close to the actual value of sine that MATLAB calculates the error as 0, even though it's not possible that the estimation is completely accurate. There's always error, it's just too small for MATLAB to recognize. Is there a way to make MATLAB consider more decimal places?

Answer: 
use [digits](http://www.mathworks.com/help/symbolic/digits.html) with [vpa](http://www.mathworks.com/help/symbolic/vpa.html) (Variable-precision accuracy). More about Variable-Precision Arithmetic [here](http://www.mathworks.com/help/symbolic/variable-precision-arithmetic_f1-5556.html)... Note that you'll need the symbolic math toolbox. If you don't have it, then you can use John D'Errico's [Variable Precision Integer Arithmetic](http://www.mathworks.com/matlabcentral/fileexchange/22725) from the file exchange..
For example, to get the answer with 1000 digits for the equation of 22/7

digits(1000)

vpa(22/7)