Proving an Absolute Value Inequality

343 Views Asked by At

I've just started reading Spivak's Calculus text (4th ed.) and am having some trouble on one of the exercises. The problem asks me to prove that if $|x-x_0|<\frac{\epsilon}{2}$ and $|y-y_0|<\frac{\epsilon}{2}$, then $|x-y-(x_0-y_0)|< \epsilon$. I've proven that it implies that $|x+y-(x_0 + y_0)|<\epsilon$ by adding the two given inequalities and using the addition triangle inequality for absolute value, but I can't find a way to apply the subtraction triangle inequality on this problem. Any help would be appreciated, thanks.

1

There are 1 best solutions below

0
On BEST ANSWER

Hints:

$$|x-y-(x_0-y_0)|=|x-x_0-(y-y_0)|\le|x-x_0|+|y-y_0|\ldots$$