Help, Invalid Trial Solution (1 Viewer)

[Sy123]

Questions

Solution the trial gave.

Now, while I was doing the past paper, the question (b)(iv) I could not solve it. So I looked over the solutions after time finished, and saw the solution...

According to the math past posts in the HSC Marathon:

A classic fallacious argument in analysis. The number of terms in this series is not fixed, so we cannot simply take the limits of each term individually and add them. If things like this were legit then we would have for example


lim (1+1/n)^n = lim 1^n = 1, as each term in the n-fold product (1+1/n)(1+1/n)...(1+1/n) tends to 1.

A little iffy about that question, because the NSW Syllabus only ever defines integral values of n (for the Binomial Expansion)...

So the trial solution is wrong in that regard for (iii) however since they used their solution for (iv). (And moreover if you can see, that they misprinted the question of iv, because in the solution they concluded that the limit to infinity of e is between 2 and 3, while in the question there was only .

Also this isnt the only part of the paper where there was a misprint, because while I was doing the past paper, there was another 1 mark question I couldnt do, which was to Show something, except on my paper it asked me to solve an impossible result...

So my question is, is it possible to do iv without resorting to invalid out of the syllabus techniques? (I proved iii using induction)

Thanks.

 

[Sanjeet]

Bump for you. Very good question but I'm not too sure

 

[asianese]

Saw a similar thing in http://www.angelfire.com/ab7/fourunit/stignatius2009.pdf

I think they're just testing concepts, like we discussed before.

(PS how do you attach photos that automatically come up? [without the link])

 

[OMGITzJustin]

Saw a similar thing in http://www.angelfire.com/ab7/fourunit/stignatius2009.pdf

I think they're just testing concepts, like we discussed before.

(PS how do you attach photos that automatically come up? [without the link])

you actually insert a picture from file/url through the list of tools next to the emoticons etc.