I don't understand where I did my work wrong. I divided all the terms by a common multiple to simplify them, so I don't see anywhere I could have done it incorrectly.

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- October 27th 2012, 02:55 AMPhizKidLimits to infinity

I don't understand where I did my work wrong. I divided all the terms by a common multiple to simplify them, so I don't see anywhere I could have done it incorrectly. - October 27th 2012, 03:00 AMMarkFLRe: Limits to infinity
In your first step, when you bring 1/x under the radicals, it needs to be 1/x^2.

- October 27th 2012, 03:24 AMjohnsomeoneRe: Limits to infinity
- October 27th 2012, 04:08 AMPhizKidRe: Limits to infinity
Oh, I'm still a little confused. Our professor just told us to divide out each term by a common factor or factor some common factor out of each term, so that's just what I did. I didn't think it mattered what kind of term it was but apparently it's something very different.

So you multiply every term by (1/x) every time?

In your first method, how did your 1/x become sqrt(1/x^2)? - October 27th 2012, 05:15 AMPlatoRe: Limits to infinity
- October 27th 2012, 06:10 AMDevenoRe: Limits to infinity
another approach:

we may assume x > 2, since we are taking the limit at "positive infinity".

thus:

, and

so:

and:

since:

(it's always (for x > 2) bigger than half the square root of x+2, right?)