% Using four-digit rounding arithmetic to compute
% "f(x) = [exp(x)-exp(-x)] / x" at x = 0.1
% with its third Maclaurin polynomial
% f(x) = 2(1+(x^2)/3!)
x = 0.1;

% x^2
x2 = roundk(roundk(x,3)^2,3);

% answer = f(x)
answer_12c = roundk(2*roundk(1+roundk(x2/factorial(3),3),3),3)