% Using four-digit rounding arithmetic to compute 
% "f(x) = [exp(x)-exp(-x)] / x" at x = 0.1
x = roundk(0.1,4);

% calculate cos(0.1) & sin(0.1)
e = roundk(exp(x),3);
e1 = roundk(exp(-x),3);

% numerator = x*cos(x)-sin(x)
% denominator = x-sin(x)
numerator = roundk(e-e1,3);
denominator = roundk(x,3);

% answer = f(x)
answer_12b = roundk(numerator/denominator,3)