Let f(x) = √(x^2 + 1) - 1 (taking the positive real square root, as usual).
When x = 10^-3, compute f(x), working to 5 significant figures at every stage of the calculation.
Show (algebraically) that f(x) =(x^2)/[√(x^2 + 1) +1].
Use this expression for f to compute f(x), again working to 5 significant figures at every stage.