#23 - Must Be True, Purpose

[SherryZ]

Hi there, thank you for your help!

June 2009 LSAT, Sec 4 RC, Q23:

I chose B but it is wrong. Is B wrong because it says Koch curve is a "natural form"?

Also, could you explain why D is right and where can I locate/infer the answer from the passage?

Thank you very much!

---Sherry

[Lucas Moreau]

Hello, Sherry,

I believe you are correct about B being wrong because it calls the Koch curve a "natural form." My inference from the passage (primarily derived from Line 40 or so, "...consider it a new language for describing complex natural and mathematical forms.") is that a "natural form" is an object found in nature, like a seashell forming a spiral, and a "mathematical form" is an object only found within mathematics, like a perfect sphere.

D is the better answer choice, and Lines 8-10 have what you need: "The Koch curve is a significant fractal in mathematics and examining it provides some insight into fractal geometry." That is the author broadcasting his/her purpose in explaining the Koch curve, to provide insight into fractal geometry (and self-similarity, which is a subset of fractal geometry).

Oh, and this isn't useful for the question itself, but if you're interested: True fractals aren't found in nature, only in mathematics, because they contain an infinite sequence of progressively smaller features. The Mandelbrot set is probably the most famous example; this picture shows what it looks like. All the little blobs on the fringe are perfect copies of the main object (er, that's mostly accurate), and if you zoomed in on them, you'd find more little blobs, and so on, forever. I think it's kinda nifty, myself.

http://en.wikipedia.org/wiki/File:Mande ... ot_set.jpg

Hope that helps,
Lucas Moreau
PowerScore

[HowardQ]

Hi,

I don't understand, E seems to describe exactly what the lines are, why is D a better answer? Is it because the question stem asks what it's purpose is and not what it exactly is?

Thanks,

[Adam Tyson]

Both answers D and E describe a particular purpose, HowardQ, but which purpose did those lines serve? The passage already told us that "an exact definition of fractals has not been established," so the description of the Koch curve couldn't be providing that exact definition. If it did, then an exact definition WOULD be established!

This should be handled by your prephrase, which should have been something fairly similar to answer D: to show something, to demonstrate or to illustrate the idea of self-similarity. Perhaps, from the prior lines, to "provide some insight into fractal geometry." Not an exact definition, but just "some insight."

Use context, and prephrase every time, and correct answers should become more obvious while wrong answers will become much less attractive. Don't go into the answer choices until you have your prephrase in mind!