by giladedelman Tue Nov 02, 2010 11:33 pm
Thanks for your post! I agree, this is a pretty dense passage.
Question 25 is irritating because we have to look out for four correct inferences and one incorrect inference.
(A) is the correct answer because the passage does not support the idea that the total number of protrusions in the Koch curve depends on the length of the initial line. In fact, it suggests the exact opposite: the protrusions are formed by taking a certain portion (a third) of the line segment, so the length is irrelevant.
(B) is incorrect it is a valid inference. At each stage of the Koch curve, you're taking a line segment and changing it into four segments each one third the length of the original.
(C) is supported in lines 27-31: "Theoretically, the Koch curve is the result of infinitely many steps in the construction process, but the finest image approximating the Koch curve will be limited by the fact that eventually the segments will get too short to be drawn or displayed."
(D) is supported because we're told that each phase of the curve is constructed by taking your line segment and making it into four equal parts. (You go from ____ to _/\_.)
(E) is supported because the length of each line segment is one third the length of the segment in the stage before it, so its length depends on the length of the preceding segment, all the way back to the beginning.
Question 27 is also an inference question. We're looking for a statement with concrete support in the text.
(D) is correct because the passage describes the development and applications of fractal theory at great length, but tells us that "an exact definition of fractals has not been established." So you can have development and applications even before having a precise definition.
(A) is unsupported. We aren't told that the appeal is limited in any particular way.
(B) is out of scope; the passage doesn't address recent breakthroughs in mathematical theory.
(C) sort of resembles what the pro-fractal crowd says, but they never actually say that fractal geometry can replace traditional geometry; nor does engineering come up.
(E), on the other hand, sort of leans to the anti-fractal crew, but again, the passage never lays out the requirements for "enthusiastic support among a significant number of mathematicians." So there's no support for this.
Did that clear these up for you? Let me know if you still have questions.