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GRE Mathematics (REA) - The Best Test Prep for the GRE (Test Preps)
O. P. Agrawal, T. Elsner, J. Robertson, J. T. Wilson
Research & Education Association, 2002-06-01
Price: $28.95
ASIN: 0878916377 Keywords: Education, GRE, History, Mathematics, Reference, Science, Test Prep Central
Reviews:
For the most part, a complete waste of time.
Good
No substantially new problems since the first edition
Good problems, but many errors
If you enjoy feeling inept in math, this is the book for you
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Many reviewers have pointed out that the practice tests in this volume are harder than the actual GRE math subject test, which I found to be true. It's not that this is, a fortiori, a bad thing; sometimes training on harder tests makes the real thing seem much easier in contrast. However, the practice tests in this book are not just harder than the actual test, but quite different in terms of the skill set they seem to require. So if you practice from this book, you're really not practicing the types of questions you'll see on the GRE.
More specifically, there are plenty of questions in the REA book that require odd leaps of intuition that even the more seasoned mathematician is not likely to make, at least not without a lot of time to sit down and play with the problem. (Of course this is an impossibility given the tight schedule they give you on the real exam to answer 66 questions!)
As an example (and this is a bit rough since it's not easy typing up math expressions like this):
SUM (from 1 to m) arctan( 1 / ( n^2 + n + 1 ) )
I won't detail the contorted series of substitutions and simplifications the answer key suggests. Perhaps I'm being naive, but I'm in my fifth year of graduate study and I have never come across a problem like this on a timed test. This is more like the kind of brain-teaser you might find in one of the common math journals. (Think Putnam exam problem, but not really as difficult.) Needless to say, the real test does not require this kind of reasoning. Everything on the real test suggests to the well-prepared student a reasonably standard method of attack.
Unfortunately, there are a lot of these useless practice problems. They are a distraction, especially when you want to time yourself and take a full practice test. (It's easy enough to skip these when casually working problems.) It's also distracting to find questions covering relatively obscure topics. Like, what is Green's function for a 2nd order differential equation? (I guess the solution guide "explained" it to me.) I've taught differential equations from multiple books for years and I've never seen it. I'm sure somebody covers in it their curriculum, but can we really expect that everyone should know how to compute Green's function?
A lot has been said as well about typos. Again, perhaps I am wrong about the new edition, but I suspect many of these remain. Worse than the typos for me was the typesetting. In this, the modern age of technology, why, I ask, does this book still look like it was produced on a typewriter? We've had TeX for many years now, for crying out loud! A few of my favorite typographic blunders:
In a discussion of continuity, an appropriate looking epsilon symbol appears, and then in the very same line, the symbol for element inclusion in a set (which sort of looks like an e I guess) plays the role of the very same epsilon. Later in the book, the epsilon symbols reappears, but now used as element inclusion.
In another solution, the Greek letter alpha appears, and then suddenly turns into the symbol for "proportional to"--only vaguely resembling an alpha in the most superficial of characteristics--again in the very same line.
The most unforgivable offense is the following "computation" of the number non-isomorphic abelian groups of order 40:
The answer according to REA? Seven. Here's their explanation:
"Non-isomorphic abelian groups of the same order, n, are effectively the direct products Z_n1 X Z_n2 X ... X Z_nk where n_1 x n_2 x ... n_k = n and each n_i is a divisor of n. In this case, the products yielding 40 are 40, 10 x 4, 8 x 5, 20 x 2, 10 x 2 x 2, 5 x 4 x 2, and 5 x 2 x 2 x 2."
Huh!?! I'm pretty sure the answer is three. The very elementary theorem from your first abstract algebra course states:
Z_m = Z_m1 X Z_m2 iff m1 and m2 are relatively prime.
Hence,
Z_40 = Z_8 X Z_5
Z_10 X Z_4 = Z_5 X Z_2 X Z_4 = Z_20 X Z_2
Z_10 X Z_2 X Z_2 = Z_5 X Z_2 X Z_2 X Z_2
Yup. Three isomorphism classes, not seven. Heaven help the poor sap who uses this book to "remember" the facts long ago forgotten.
I admit, truly egregious errors like this are rare. But little slips, typos, errors, and miscalculations abound, all laid out in ugly, ugly typeface.
It's a shame. There are so few resources out there to help students practice for this test. The ETS book is great, but it has no detailed solutions; only the answer key.
Oh, yeah, and the math review that occupies the first half ot this tome? It sucks too.