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Feb 23, 2018 at 19:03 comment added Brendan W. Sullivan @SantiagoCanez: I like your idea, too, so I added a suggestion: present the method I shared and then yours, then discuss with the students to compare the two.
Feb 23, 2018 at 19:03 history edited Brendan W. Sullivan CC BY-SA 3.0
fixed typo in an inequality, added comment addressing another user's suggestion
Feb 23, 2018 at 15:25 comment added Santiago Canez This is a nice example, but as in my comment to OP I think the way you work through it misses the point: the goal should be to bound the thing $\left|\frac2{x+1}-2\right|$ you want to make smaller than $\epsilon$ by the thing $|x-0|$ you have some control over, so students should work to manipulate the former to get something involving the latter directly. In this case some algebra gives $\frac{2|x|}{|x+1|}$, and now the point should be to bound everything which is not $|x|$ by a constant, which here requires finding a lower bound on $|x+1|$ and hence again a "minimum" choice for $\delta$.
Feb 23, 2018 at 1:24 vote accept benblumsmith
Feb 22, 2018 at 19:45 history answered Brendan W. Sullivan CC BY-SA 3.0