Is My Approach to Proving lim (x^3+2x^2) = 1 Using ε/δ Definition Correct?

[cwz]

Homework Statement

Prove using ε/δ definition,

lim x tends to -1 (x^3+2x^2) = 1

Homework Equations

The Attempt at a Solution

I have done to the step where δ(δ^2-δ-1) ≤ δ ≤ ε

so i choose ε=min(2,ε)

Not sure whether I am correct or not

 

[vela]

I hope you realize that
$$\lim_{x \to -1} (x^3+2x^2) \ne 1$$ so you're going to have a tough time proving it. In any case, you need to show more of your work. We can't see your paper or read your mind to see what you actually did.

 

[pasmith]

i hope you realize that
$$\lim_{x \to -1} (x^3+2x^2) \ne 1$$

(-1)^3 + 2(-1)^2 = -1 + 2 = 1. Last time I checked, x^3 + 2x^2 was continuous everywhere.

 

[vela]

Well, now I feel like an idiot. And I checked it over and over and kept getting -1.